test: split out test-pidfd-util from test-process-util

The tested function pidfd_get_inode_id_self_cached() is provided by
pidfd-util.c. Let's introduce a new unit test for the file.

src/test/meson.build

@@ -171,6 +171,7 @@ simple_tests += files(
         'test-path-lookup.c',
         'test-path-util.c',
         'test-percent-util.c',
+        'test-pidfd-util.c',
         'test-pidref.c',
         'test-plymouth-util.c',
         'test-pressure.c',

src/test/test-pidfd-util.c

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "errno-util.h"
+#include "format-util.h"
+#include "pidfd-util.h"
+#include "process-util.h"
+#include "tests.h"
+
+TEST(pidfd_get_inode_id_self_cached) {
+        int r;
+
+        log_info("pid=" PID_FMT, getpid_cached());
+
+        uint64_t id;
+        r = pidfd_get_inode_id_self_cached(&id);
+        if (ERRNO_IS_NEG_NOT_SUPPORTED(r))
+                log_info("pidfdid not supported");
+        else {
+                assert(r >= 0);
+                log_info("pidfdid=%" PRIu64, id);
+        }
+}
+
+DEFINE_TEST_MAIN(LOG_DEBUG);

src/test/test-process-util.c

@@ -27,7 +27,6 @@
 #include "log.h"
 #include "namespace-util.h"
 #include "parse-util.h"
-#include "pidfd-util.h"
 #include "pidref.h"
 #include "process-util.h"
 #include "procfs-util.h"
@@ -1075,21 +1074,6 @@ TEST(pidref_from_same_root_fs) {
         ASSERT_OK_ZERO(pidref_from_same_root_fs(&child2, &self));
 }
 
-TEST(pidfd_get_inode_id_self_cached) {
-        int r;
-
-        log_info("pid=" PID_FMT, getpid_cached());
-
-        uint64_t id;
-        r = pidfd_get_inode_id_self_cached(&id);
-        if (ERRNO_IS_NEG_NOT_SUPPORTED(r))
-                log_info("pidfdid not supported");
-        else {
-                assert(r >= 0);
-                log_info("pidfdid=%" PRIu64, id);
-        }
-}
-
 TEST(getenv_for_pid) {
         _cleanup_strv_free_ char **copy_env = NULL;
         pid_t pid = getpid_cached();