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/3c515.c b/drivers/net/3c515.c
index 2e17837..569e269 100644
--- a/drivers/net/3c515.c
+++ b/drivers/net/3c515.c
@@ -992,7 +992,7 @@
 		if (!(inw(ioaddr + EL3_STATUS) & CmdInProgress))
 			break;
 	outw(TxEnable, ioaddr + EL3_CMD);
-	dev->trans_start = jiffies;
+	dev->trans_start = jiffies; /* prevent tx timeout */
 	dev->stats.tx_errors++;
 	dev->stats.tx_dropped++;
 	netif_wake_queue(dev);
@@ -1055,7 +1055,6 @@
 				prev_entry->status &= ~0x80000000;
 			netif_wake_queue(dev);
 		}
-		dev->trans_start = jiffies;
 		return NETDEV_TX_OK;
 	}
 	/* Put out the doubleword header... */
@@ -1091,7 +1090,6 @@
 		outw(SetTxThreshold + (1536 >> 2), ioaddr + EL3_CMD);
 #endif				/* bus master */
 
-	dev->trans_start = jiffies;
 
 	/* Clear the Tx status stack. */
 	{