net: add skb_get_tx_queue() helper

Replace occurences of skb_get_queue_mapping() and follow-up
netdev_get_tx_queue() with an actual helper function.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4298013..dfc1d8b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1747,6 +1747,12 @@
 	return &dev->_tx[index];
 }
 
+static inline struct netdev_queue *skb_get_tx_queue(const struct net_device *dev,
+						    const struct sk_buff *skb)
+{
+	return netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
+}
+
 static inline void netdev_for_each_tx_queue(struct net_device *dev,
 					    void (*f)(struct net_device *,
 						      struct netdev_queue *,