basic/stat-util: remove unused null_or_empty_fd()

src/basic/stat-util.c

@@ -152,17 +152,6 @@ int null_or_empty_path_with_root(const char *fn, const char *root) {
         return null_or_empty(&st);
 }
 
-int null_or_empty_fd(int fd) {
-        struct stat st;
-
-        assert(fd >= 0);
-
-        if (fstat(fd, &st) < 0)
-                return -errno;
-
-        return null_or_empty(&st);
-}
-
 static int fd_is_read_only_fs(int fd) {
         struct statvfs st;