btrfs: Fix memory leak in btrfs_read_fs_root_no_radix()

In btrfs_read_fs_root_no_radix(), 'root' is not freed if
btrfs_search_slot() returns error.

Signed-off-by: Tsutomu Itoh <[e-mail]>
Signed-off-by: Chris Mason <[e-mail]>

fs/btrfs/disk-io.c

···
 	}
 	btrfs_free_path(path);
 	if (ret) {
+		kfree(root);
 		if (ret > 0)
 			ret = -ENOENT;
 		return ERR_PTR(ret);