em_meta: avoid one dev_put()

Another rcu conversion to avoid one dev_hold()/dev_put() pair
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/em_meta.c

@@ -303,17 +303,17 @@ META_COLLECTOR(var_sk_bound_if)
 {
 	SKIP_NONLOCAL(skb);
 
-	 if (skb->sk->sk_bound_dev_if == 0) {
+	if (skb->sk->sk_bound_dev_if == 0) {
 		dst->value = (unsigned long) "any";
 		dst->len = 3;
-	 } else  {
+	} else {
 		struct net_device *dev;
 
-		dev = dev_get_by_index(&init_net, skb->sk->sk_bound_dev_if);
+		rcu_read_lock();
+		dev = dev_get_by_index_rcu(&init_net, skb->sk->sk_bound_dev_if);
 		*err = var_dev(dev, dst);
-		if (dev)
-			dev_put(dev);
-	 }
+		rcu_read_unlock();
+	}
 }
 
 META_COLLECTOR(int_sk_refcnt)