tree-wide: use the same comment for work-around initializations

This should make it easier to remove those warnings when the compiler
gets smarter. Not sure if I got them all...

Double space before the comment start to make it easier to separate from the
preceding line.

src/basic/cgroup-util.c

@@ -660,7 +660,7 @@ int cg_remove_xattr(const char *controller, const char *path, const char *name)
 
 int cg_pid_get_path(const char *controller, pid_t pid, char **ret_path) {
         _cleanup_fclose_ FILE *f = NULL;
-        const char *fs, *controller_str = NULL; /* silence gcc warning about unitialized variable */
+        const char *fs, *controller_str = NULL;  /* avoid false maybe-uninitialized warning */
         int unified, r;
 
         assert(pid >= 0);

src/basic/copy.c

@@ -1072,7 +1072,7 @@ int copy_file_full(
 
         _cleanup_close_ int fdf = -1;
         struct stat st;
-        int fdt = -1, r;
+        int r, fdt = -1;  /* avoid false maybe-uninitialized warning */
 
         assert(from);
         assert(to);

src/core/main.c

@@ -1367,7 +1367,7 @@ static int status_welcome(void) {
 
 static int write_container_id(void) {
         const char *c;
-        int r = 0; /* silence gcc warning about r being unitialized below */
+        int r = 0;  /* avoid false maybe-uninitialized warning */
 
         c = getenv("container");
         if (isempty(c))

src/test/test-capability.c

@@ -242,7 +242,7 @@ static void test_ensure_cap_64bit(void) {
 }
 
 int main(int argc, char *argv[]) {
-        bool run_ambient = false; /* unnecessary initialization to silence gcc warning */
+        bool run_ambient = false;  /* avoid false maybe-uninitialized warning */
 
         test_setup_logging(LOG_INFO);