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/sonic.c b/drivers/net/sonic.c
index e5d6732..26e25d7 100644
--- a/drivers/net/sonic.c
+++ b/drivers/net/sonic.c
@@ -174,7 +174,7 @@
 	/* Try to restart the adaptor. */
 	sonic_init(dev);
 	lp->stats.tx_errors++;
-	dev->trans_start = jiffies;
+	dev->trans_start = jiffies; /* prevent tx timeout */
 	netif_wake_queue(dev);
 }
 
@@ -263,8 +263,6 @@
 
 	SONIC_WRITE(SONIC_CMD, SONIC_CR_TXP);
 
-	dev->trans_start = jiffies;
-
 	return NETDEV_TX_OK;
 }