[NETFILTER]: nf_queue: check if rerouter is present before using it

Every rerouter needs to provide a save and a reroute function, we don't
need to check for them. But we do need to check if a rerouter is registered
at all for the current family, with bridging for example packets of
unregistered families can hit nf_queue.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netfilter/nf_queue.c

@@ -155,13 +155,13 @@ int nf_queue(struct sk_buff **skb,
 		if (physoutdev) dev_hold(physoutdev);
 	}
 #endif
-	if (queue_rerouter[pf]->save)
+	if (queue_rerouter[pf])
 		queue_rerouter[pf]->save(*skb, info);
 
 	status = queue_handler[pf]->outfn(*skb, info, queuenum,
 					  queue_handler[pf]->data);
 
-	if (status >= 0 && queue_rerouter[pf]->reroute)
+	if (status >= 0 && queue_rerouter[pf])
 		status = queue_rerouter[pf]->reroute(skb, info);
 
 	read_unlock(&queue_handler_lock);