atm/br2684: netif_stop_queue() when atm device busy and netif_wake_queue()...

atm/br2684: netif_stop_queue() when atm device busy and netif_wake_queue() when we can send packets again.

This patch removes the call to dev_kfree_skb() when the atm device is busy.
Calling dev_kfree_skb() causes heavy packet loss then the device is under
heavy load, the more correct behavior should be to stop the upper layers,
then when the lower device can queue packets again wake the upper layers.

Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>