net: sched: Simplify em_ipset_match

em->net is always set and always available, use it in preference
to dev_net(skb->dev).
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/sched/em_ipset.c

@@ -92,8 +92,8 @@ static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
 
 	rcu_read_lock();
 
-	if (dev && skb->skb_iif)
-		indev = dev_get_by_index_rcu(dev_net(dev), skb->skb_iif);
+	if (skb->skb_iif)
+		indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
 
 	acpar.in      = indev ? indev : dev;
 	acpar.out     = dev;