netpoll: call ->ndo_select_queue() in tx path

In netpoll tx path, we miss the chance of calling ->ndo_select_queue(),
thus could cause problems when bonding is involved.

This patch makes dev_pick_tx() extern (and rename it to netdev_pick_tx())
to let netpoll call it in netpoll_send_skb_on_dev().

Reported-by: Sylvain Munaut <s.munaut@whatever-company.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Tested-by: Sylvain Munaut <s.munaut@whatever-company.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index bbda819..707b124 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2396,8 +2396,8 @@
 #endif
 }
 
-static struct netdev_queue *dev_pick_tx(struct net_device *dev,
-					struct sk_buff *skb)
+struct netdev_queue *netdev_pick_tx(struct net_device *dev,
+				    struct sk_buff *skb)
 {
 	int queue_index;
 	const struct net_device_ops *ops = dev->netdev_ops;
@@ -2571,7 +2571,7 @@
 
 	skb_update_prio(skb);
 
-	txq = dev_pick_tx(dev, skb);
+	txq = netdev_pick_tx(dev, skb);
 	q = rcu_dereference_bh(txq->qdisc);
 
 #ifdef CONFIG_NET_CLS_ACT