ifb: dont hard code inet_net use

ifb should lookup devices in the appropriate namespace.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ifb.c

@@ -90,7 +90,7 @@ static void ri_tasklet(unsigned long dev)
 		u64_stats_update_end(&dp->tsync);
 
 		rcu_read_lock();
-		skb->dev = dev_get_by_index_rcu(&init_net, skb->skb_iif);
+		skb->dev = dev_get_by_index_rcu(dev_net(_dev), skb->skb_iif);
 		if (!skb->dev) {
 			rcu_read_unlock();
 			dev_kfree_skb(skb);