xen-netfront: Remove the meaningless code

The function netif_set_real_num_tx_queues() will return -EINVAL if
the second parameter < 1, so call this function with the second
parameter set to 0 is meaningless.
Signed-off-by: NLiang Li <liang.z.li@intel.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/xen-netfront.c

@@ -1245,10 +1245,6 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
 	np                   = netdev_priv(netdev);
 	np->xbdev            = dev;
 
-	/* No need to use rtnl_lock() before the call below as it
-	 * happens before register_netdev().
-	 */
-	netif_set_real_num_tx_queues(netdev, 0);
 	np->queues = NULL;
 
 	err = -ENOMEM;
@@ -1900,9 +1896,6 @@ static int talk_to_netback(struct xenbus_device *dev,
 	xennet_disconnect_backend(info);
 	kfree(info->queues);
 	info->queues = NULL;
-	rtnl_lock();
-	netif_set_real_num_tx_queues(info->netdev, 0);
-	rtnl_unlock();
  out:
 	return err;
 }