net: call dev_queue_xmit_nit() after skb_dst_drop()

Avoid some atomic ops on dst refcount, calling dev_queue_xmit_nit()
after skb_dst_drop() in dev_hard_start_xmit().

When queueing a packet into af_packet socket, we drop dst anyway.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -2022,9 +2022,6 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
 	int rc = NETDEV_TX_OK;
 
 	if (likely(!skb->next)) {
-		if (!list_empty(&ptype_all))
-			dev_queue_xmit_nit(skb, dev);
-
 		/*
 		 * If device doesnt need skb->dst, release it right now while
 		 * its hot in this cpu cache
@@ -2032,6 +2029,9 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
 			skb_dst_drop(skb);
 
+		if (!list_empty(&ptype_all))
+			dev_queue_xmit_nit(skb, dev);
+
 		skb_orphan_try(skb);
 
 		if (vlan_tx_tag_present(skb) &&