basic/stat-util: add null_or_empty_path_with_root()

src/basic/stat-util.h

@@ -31,9 +31,13 @@ static inline int dir_is_populated(const char *path) {
 }
 
 bool null_or_empty(struct stat *st) _pure_;
-int null_or_empty_path(const char *fn);
+int null_or_empty_path_with_root(const char *fn, const char *root);
 int null_or_empty_fd(int fd);
 
+static inline int null_or_empty_path(const char *fn) {
+        return null_or_empty_path_with_root(fn, NULL);
+}
+
 int path_is_read_only_fs(const char *path);
 
 int files_same(const char *filea, const char *fileb, int flags);