Btrfs: add missing error check in incremental send

Function wait_for_parent_move() returns negative value if an error
happened, 0 if we don't need to wait for the parent's move, and
1 if the wait is needed.
Before this change an error return value was being treated like the
return value 1, which was not correct.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>

fs/btrfs/send.c

@@ -3227,7 +3227,10 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
 				 * dirs, we always have one new and one deleted
 				 * ref. The deleted ref is ignored later.
 				 */
-				if (wait_for_parent_move(sctx, cur)) {
+				ret = wait_for_parent_move(sctx, cur);
+				if (ret < 0)
+					goto out;
+				if (ret) {
 					ret = add_pending_dir_move(sctx,
 								   cur->dir);
 					*pending_move = 1;