net: trans_start cleanups

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

Exceptions are NETIF_F_LLTX drivers

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sundance.c b/drivers/net/sundance.c
index da45f01..1680325 100644
--- a/drivers/net/sundance.c
+++ b/drivers/net/sundance.c
@@ -972,7 +972,7 @@
 
 	dev->if_port = 0;
 
-	dev->trans_start = jiffies;
+	dev->trans_start = jiffies; /* prevent tx timeout */
 	dev->stats.tx_errors++;
 	if (np->cur_tx - np->dirty_tx < TX_QUEUE_LEN - 4) {
 		netif_wake_queue(dev);
@@ -1084,7 +1084,6 @@
 	} else {
 		netif_stop_queue (dev);
 	}
-	dev->trans_start = jiffies;
 	if (netif_msg_tx_queued(np)) {
 		printk (KERN_DEBUG
 			"%s: Transmit frame #%d queued in slot %d.\n",