IB/mlx5: Fix steering resource leak

Fix multicast flow rule leak on adding unicast rule failure.

Fixes: 038d2ef8 ('IB/mlx5: Add flow steering support')
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/main.c

@@ -1861,6 +1861,7 @@ static struct mlx5_ib_flow_handler *create_leftovers_rule(struct mlx5_ib_dev *de
 						 &leftovers_specs[LEFTOVERS_UC].flow_attr,
 						 dst);
 		if (IS_ERR(handler_ucast)) {
+			mlx5_del_flow_rule(handler->rule);
 			kfree(handler);
 			handler = handler_ucast;
 		} else {