maint: update to latest gnulib

The usual portability fixes; and this includes a fix that adds
a new syntax check for double semicolons (commit 28de556d fixed
some, but gnulib found a better check).

* .gnulib: Update to latest.
* src/xenconfig/xen_common.c (xenFormatConfigCommon): Fix offender.
Signed-off-by: NEric Blake <eblake@redhat.com>

.gnulib @ 9565c3be

-Subproject commit 2d280742a9e30088aa169f53353765d5daafe4c0
+Subproject commit 9565c3be73eb6d76b7b42a21d68d2e00a62abb6d

src/xenconfig/xen_common.c

@@ -2034,7 +2034,7 @@ xenFormatConfigCommon(virConfPtr conf,
         return -1;
 
     if (xenFormatCPUFeatures(conf, def, xendConfigVersion) < 0)
-        return -1;;
+        return -1;
 
     if (xenFormatCDROM(conf, def, xendConfigVersion) < 0)
         return -1;