mufs: free tree object if owned by struct mufs_dir in mufs_closedir()

source/fs/mufs/dir.c

@@ -166,6 +166,9 @@ void mufs_closedir(struct mufs_dir *dir)
 	if (!dir)
 		return;
 
+	if (dir->tree && dir->tree != &dir->fs->root)
+		free(dir->tree);
+
 	free(dir);
 }