netfilter: nf_queue: remove leftover synchronize_rcu

Its no longer needed after commit 87029970
("netfilter: nf_queue: move hookfn registration out of struct net").
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nfnetlink_queue.c

@@ -1527,15 +1527,9 @@ static void __net_exit nfnl_queue_net_exit(struct net *net)
 		WARN_ON_ONCE(!hlist_empty(&q->instance_table[i]));
 }
 
-static void nfnl_queue_net_exit_batch(struct list_head *net_exit_list)
-{
-	synchronize_rcu();
-}
-
 static struct pernet_operations nfnl_queue_net_ops = {
 	.init		= nfnl_queue_net_init,
 	.exit		= nfnl_queue_net_exit,
-	.exit_batch	= nfnl_queue_net_exit_batch,
 	.id		= &nfnl_queue_net_id,
 	.size		= sizeof(struct nfnl_queue_net),
 };