bcachefs: fix leak in bch2_gc_write_reflink_key

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_gc.c

@@ -1587,7 +1587,7 @@ static int bch2_gc_write_reflink_key(struct btree_trans *trans,
 		struct bkey_i *new = bch2_bkey_make_mut_noupdate(trans, k);
 		ret = PTR_ERR_OR_ZERO(new);
 		if (ret)
-			return ret;
+			goto out;
 
 		if (!r->refcount)
 			new->k.type = KEY_TYPE_deleted;
@@ -1595,6 +1595,7 @@ static int bch2_gc_write_reflink_key(struct btree_trans *trans,
 			*bkey_refcount(bkey_i_to_s(new)) = cpu_to_le64(r->refcount);
 		ret = bch2_trans_update(trans, iter, new, 0);
 	}
+out:
 fsck_err:
 	printbuf_exit(&buf);
 	return ret;