net: remove redundant code in dev_hard_start_xmit()

This reverts commit 068a2de5 (net: release dst entry while
cache-hot for GSO case too)

Before GSO packet segmentation, we already take care of skb->dst if it
can be released.

There is no point adding extra test for every segment in the gso loop.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -2546,13 +2546,6 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
 		skb->next = nskb->next;
 		nskb->next = NULL;
 
-		/*
-		 * If device doesn't need nskb->dst, release it right now while
-		 * its hot in this cpu cache
-		 */
-		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
-			skb_dst_drop(nskb);
-
 		if (!list_empty(&ptype_all))
 			dev_queue_xmit_nit(nskb, dev);