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/pcmcia/nmclan_cs.c b/drivers/net/pcmcia/nmclan_cs.c
index c516c19..ca4efd2 100644
--- a/drivers/net/pcmcia/nmclan_cs.c
+++ b/drivers/net/pcmcia/nmclan_cs.c
@@ -903,7 +903,7 @@
 #else /* #if RESET_ON_TIMEOUT */
   printk("NOT resetting card\n");
 #endif /* #if RESET_ON_TIMEOUT */
-  dev->trans_start = jiffies;
+  dev->trans_start = jiffies; /* prevent tx timeout */
   netif_wake_queue(dev);
 }
 
@@ -945,8 +945,6 @@
       outb(skb->data[skb->len-1], ioaddr + AM2150_XMT);
     }
 
-    dev->trans_start = jiffies;
-
 #if MULTI_TX
     if (lp->tx_free_frames > 0)
       netif_start_queue(dev);