If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
Otherwise, this info will not be added when errp == &fatal_err
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such cases.

This commit (together with its neighbors) was generated by

git grep -l 'error_\(append_hint\|prepend\)(errp' | while read f; do \
spatch --sp-file scripts/coccinelle/fix-error-add-info.cocci \
--in-place $f; done

and then

./python/commit-per-subsystem.py MAINTAINERS "$(< auto-msg)"

(auto-msg was a file with this commit message)

and then by hand, for not maintained changed files:

git commit -m "<SUB-SYSTEM>: $(< auto-msg)" <FILES>

Still, for backporting it may be more comfortable to use only the first
command and then do one huge commit.

Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 util/qemu-sockets.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index bcc06d0e01..396e028ae0 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -861,6 +861,7 @@ static int unix_listen_saddr(UnixSocketAddress *saddr,
                              int num,
                              Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     struct sockaddr_un un;
     int sock, fd;
     char *pathbuf = NULL;
@@ -936,6 +937,7 @@ err:
 
 static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     struct sockaddr_un un;
     int sock, rc;
     size_t pathlen;
-- 
2.21.0