RDS: TCP: unregister_netdevice_notifier() in error path of rds_tcp_init_net

If some error is encountered in rds_tcp_init_net, make sure to
unregister_netdevice_notifier(), else we could trigger a panic
later on, when the modprobe from a netns fails.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds/tcp.c

@@ -659,6 +659,8 @@ static int rds_tcp_init(void)
 out_pernet:
 	unregister_pernet_subsys(&rds_tcp_net_ops);
 out_slab:
+	if (unregister_netdevice_notifier(&rds_tcp_dev_notifier))
+		pr_warn("could not unregister rds_tcp_dev_notifier\n");
 	kmem_cache_destroy(rds_tcp_conn_slab);
 out:
 	return ret;