Assorted cleanups for #42978 (#43051)

https://github.com/systemd/systemd/pull/42978

src/shared/rm-rf.c

@@ -444,14 +444,8 @@ int rm_rf_at(int dir_fd, const char *path, RemoveFlags flags) {
         /* We refuse to clean the root file system with this call. This is extra paranoia to never cause a
          * really seriously broken system. */
         r = path_is_root_at(dir_fd, path);
-        if (r == -ENOENT) {
-                struct stat st;
-
-                if (fstatat(dir_fd, path, &st, AT_SYMLINK_NOFOLLOW) < 0)
-                        r = -errno;
-                else
-                        r = 0; /* The entry exists, but is most likely a dangling symlink. */
-        }
+        if (r == -ENOENT)
+                r = RET_NERRNO(faccessat(dir_fd, path, F_OK, AT_SYMLINK_NOFOLLOW));
         if (FLAGS_SET(flags, REMOVE_MISSING_OK) && r == -ENOENT)
                 return 0;
         if (r < 0)

src/shared/shift-uid.c

@@ -297,7 +297,7 @@ static int is_fs_fully_userns_compatible(const struct statfs *sfs) {
 
 static int recurse_fd(int input_fd, const struct stat *st, uid_t shift, bool is_toplevel) {
         _cleanup_closedir_ DIR *d = NULL;
-        _cleanup_close_ int fd = input_fd;
+        _cleanup_close_ int fd = TAKE_FD(input_fd);
         bool changed = false;
         struct statfs sfs;
         int r;