bnx2: fixing a timout error due not refreshing TX timers correctly

When running the following script on an active bnx2 interface:

while(true); do ifconfig ethX mtu 9000; ifconfig ethX mtu 1500; done

A timeout error appears and dumps the following stack:

NETDEV WATCHDOG: eth4 (bnx2): transmit queue 0 timed out
------------[ cut here ]------------
Badness at net/sched/sch_generic.c:261
<snip>

This patch just fixes the way that ->trans_start is refreshed.
Signed-off-by: NBreno Leitao <leitao@linux.vnet.ibm.com>
Acked-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bnx2.c

@@ -654,9 +654,17 @@ bnx2_netif_stop(struct bnx2 *bp)
 {
 	bnx2_cnic_stop(bp);
 	if (netif_running(bp->dev)) {
+		int i;
+
 		bnx2_napi_disable(bp);
 		netif_tx_disable(bp->dev);
-		bp->dev->trans_start = jiffies;	/* prevent tx timeout */
+		/* prevent tx timeout */
+		for (i = 0; i <  bp->dev->num_tx_queues; i++) {
+			struct netdev_queue *txq;
+
+			txq = netdev_get_tx_queue(bp->dev, i);
+			txq->trans_start = jiffies;
+		}
 	}
 }