Various fixes for building with GCC 10.

Taken from Debian:
https://sources.debian.org/patches/jfsutils/1.1.15-5/gcc10_fix-1.patch/

--- jfsutils-1.1.15.old/fscklog/display.c	2005-11-22 21:43:54.000000000 +0100
+++ jfsutils-1.1.15.new/fscklog/display.c	2020-05-21 18:15:13.410617620 +0200
@@ -54,7 +54,7 @@
  * output: fsck extracted service log I/O buffer
  *
  */
-char xchklog_buffer[XCHKLOG_BUFSIZE];
+static char xchklog_buffer[XCHKLOG_BUFSIZE];
 
 /* + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
  *
diff -ur --exclude '*.o' --exclude '*.a' jfsutils-1.1.15.old/libfs/logredo.c jfsutils-1.1.15.new/libfs/logredo.c
--- jfsutils-1.1.15.old/libfs/logredo.c	2005-11-22 21:43:55.000000000 +0100
+++ jfsutils-1.1.15.new/libfs/logredo.c	2020-05-21 18:19:44.927703271 +0200
@@ -87,9 +87,9 @@
  *    S T U F F    F O R    T H E    L O G
  *
  */
-struct logsuper logsup;		/* log super block */
-int32_t numdoblk;		/* number of do blocks used     */
-int32_t numnodofile;		/* number of nodo file blocks used  */
+static struct logsuper logsup;		/* log super block */
+static int32_t numdoblk;		/* number of do blocks used     */
+static int32_t numnodofile;		/* number of nodo file blocks used  */
 int32_t numExtDtPg = 0;		/* number of extended dtpage blocks used  */
 
 /*
@@ -129,7 +129,7 @@
  */
 
 /* buffer header table */
-struct bufhdr {
+static struct bufhdr {
 	int16_t next;		/* 2: next on free/lru list */
 	int16_t prev;		/* 2: previous on free/lru list */
 	int16_t hnext;		/* 2: next on hash chain */
@@ -142,7 +142,7 @@
 } bufhdr[NBUFPOOL];		/* (24) */
 
 /* buffer table */
-struct bufpool {
+static struct bufpool {
 	char bytes[PSIZE];
 } buffer[NBUFPOOL - 1];
 
@@ -151,15 +151,16 @@
  *
  * log has its own 4 page buffer pool.
  */
-uint8_t afterdata[LOGPSIZE * 2];	/* buffer to read in redopage data */
+static uint8_t afterdata[LOGPSIZE * 2];	/* buffer to read in redopage data */
 
 /*
  * Miscellaneous
  */
-caddr_t prog;			/* Program name */
-int32_t mntcnt, bufsize;
-char *mntinfo;
-int32_t retcode;		/* return code from logredo    */
+static caddr_t prog;			/* Program name */
+extern int32_t mntcnt;
+static int32_t bufsize;
+static char *mntinfo;
+static int32_t retcode;		/* return code from logredo    */
 int end_of_transaction = 0;
 
 /*
services</a>/<a href='/guix/log/gnu/services/telephony.scm?id=37076a20f9b8eb17566dfaaef7858205b2e71545'>telephony.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/services/telephony.scm?id=37076a20f9b8eb17566dfaaef7858205b2e71545&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-12-22 00:31:41 +0100'>2023-12-22</span></td><td><a href='/guix/commit/gnu/services/telephony.scm?id=62a08abea75b234b2ada905acb9df27406c6f1d2'>services: jami: Use ‘least-authority-wrapper’.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/telephony.scm (jami-configuration-&gt;command-line-arguments)
[wrapper]: New procedure.
Use it.
(jami-shepherd-services): In ‘start’ method of ‘jami’ service, use
‘fork+exec-command’ instead of ‘make-forkexec-constructor/container’.
Remove use of (gnu build shepherd).

Change-Id: Ic71c0c88477d92bf137d9d0a5832bae8721cc210
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2023-12-22 00:31:41 +0100'>2023-12-22</span></td><td><a href='/guix/commit/gnu/services/telephony.scm?id=8bd1c14997fe2393e79c19ff5f3230a88cfb9abc'>services: jami-dbus-session: Use ‘least-authority-wrapper’.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/telephony.scm (jami-shepherd-services): Use
‘least-authority-wrapper’ for ‘dbus-daemon’.  Use ‘fork+exec-command’
instead of ‘make-forkexec-constructor/container’ in the ‘start’ method’.
Remove reference to (gnu build shepherd).

Reviewed-by: Maxim Cournoyer &lt;maxim.cournoyer@gmail.com&gt;
Change-Id: I9d9f8de6ecea77950000ff64aa8c8d097dc028a0
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2023-10-07 12:41:06 -0400'>2023-10-07</span></td><td><a href='/guix/commit/gnu/services/telephony.scm?id=00a28bc435606dc98925fbae1ebe314881f35c90'>services: configuration: Add some commonly used predicates.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/configuration.scm (list-of-packages?, list-of-symbols?): New
predicate.
* gnu/services/audio.scm (list-of-symbol?): Remove.
* gnu/services/telephony.scm (string-list?): Remove.
(serialize-string-list): Rename to …
(serialize-list-of-strings): … this.
(account-fingerprint-list?, jami-account-list?): Use list-of.
* doc/guix.texi: Update it.

Signed-off-by: Maxim Cournoyer &lt;maxim.cournoyer@gmail.com&gt;
</span></span></td><td>Bruno Victal</td></tr>
<tr><td><span title='2023-10-07 12:41:05 -0400'>2023-10-07</span></td><td><a href='/guix/commit/gnu/services/telephony.scm?id=a7994ed58dc1ac3b57aa2df8508f05fd0748b3e0'>services: configuration: Use transducers within serialize-configuration.</a><span class='msg-avail'>...<span class='msg-tooltip'>Introduces 'base-transducer', a SRFI-171 based transducer that can be used as a
starting point for writing custom configuration record serializing procedures.

This also fixes the symbol maybe-value serialization test case.

* gnu/services/configuration.scm (empty-serializer?): New predicate.
(base-transducer, tfilter-maybe-value): New procedure.
(serialize-configuration): Adapt to use base-transducer.

* gnu/services/telephony.scm (jami-account-&gt;alist): Use transducers to skip
fields that are unserializable or whose field maybe-value is unset.

* tests/services/configuration.scm: Remove test-expect-fail.

Signed-off-by: Maxim Cournoyer &lt;maxim.cournoyer@gmail.com&gt;
</span></span></td><td>Bruno Victal</td></tr>