test-acl-util: output more debug info

For some reason this failed in koji build on s390x:
--- command ---
16:12:46 PATH='/builddir/build/BUILD/systemd-stable-246.1/s390x-redhat-linux-gnu:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/sbin' SYSTEMD_LANGUAGE_FALLBACK_MAP='/builddir/build/BUILD/systemd-stable-246.1/src/locale/language-fallback-map' SYSTEMD_KBD_MODEL_MAP='/builddir/build/BUILD/systemd-stable-246.1/src/locale/kbd-model-map' /builddir/build/BUILD/systemd-stable-246.1/s390x-redhat-linux-gnu/test-acl-util
--- stdout ---
-rw-r-----. 1 mockbuild mock 0 Aug  7 16:12 /tmp/test-empty.7RzmEc
other::---
--- stderr ---
Assertion 'r >= 0' failed at src/test/test-acl-util.c:42, function test_add_acls_for_user(). Aborting.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/test/test-acl-util.c b/src/test/test-acl-util.c
index df879747f5..9f0e594e67 100644
--- a/src/test/test-acl-util.c
+++ b/src/test/test-acl-util.c
@@ -7,6 +7,7 @@
 
 #include "acl-util.h"
 #include "fd-util.h"
+#include "format-util.h"
 #include "string-util.h"
 #include "tmpfile-util.h"
 #include "user-util.h"
@@ -18,6 +19,8 @@ static void test_add_acls_for_user(void) {
         uid_t uid;
         int r;
 
+        log_info("/* %s */", __func__);
+
         fd = mkostemp_safe(fn);
         assert_se(fd >= 0);
 
@@ -39,6 +42,7 @@ static void test_add_acls_for_user(void) {
                 uid = getuid();
 
         r = add_acls_for_user(fd, uid);
+        log_info_errno(r, "add_acls_for_user(%d, "UID_FMT"): %m", fd, uid);
         assert_se(r >= 0);
 
         cmd = strjoina("ls -l ", fn);