macvlan: replace kfree_skb by consume_skb for drop profiles

Replace the kfree_skb() by consume_skb() to be drop monitor(dropwatch,
perf) friendly.

Signed-off-by: Yang Wei <yang.wei9@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index fc726ce..6d06717 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -337,7 +337,7 @@ static void macvlan_process_broadcast(struct work_struct *w)
 
 		if (src)
 			dev_put(src->dev);
-		kfree_skb(skb);
+		consume_skb(skb);
 	}
 }