net: dont update dev->trans_start in 10GB drivers

Followup of commits 9d21493b4b
and 08baf56108
(net: tx scalability works : trans_start)
(net: txq_trans_update() helper)

Now that core network takes care of trans_start updates, dont do it
in drivers themselves, if possible. Multi queue drivers can
avoid one cache miss (on dev->trans_start) in their start_xmit()
handler.

Exceptions are NETIF_F_LLTX drivers (vxge & tehuti)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netxen/netxen_nic_main.c

@@ -1496,7 +1496,6 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 	netxen_nic_update_cmd_producer(adapter, tx_ring, producer);
 
 	adapter->stats.xmitcalled++;
-	netdev->trans_start = jiffies;
 
 	return NETDEV_TX_OK;