bcachefs: Fix an assertion

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

fs/bcachefs/btree_update_leaf.c

@@ -490,7 +490,7 @@ int __bch2_btree_insert_at(struct btree_insert *trans)
 			bch2_btree_iter_verify_locks(linked);
 			BUG_ON((trans->flags & BTREE_INSERT_NOUNLOCK) &&
 			       trans->did_work &&
-			       linked->uptodate >= BTREE_ITER_NEED_RELOCK);
+			       !btree_node_locked(linked, 0));
 		}
 
 		/* make sure we didn't lose an error: */