Under heavy traffic load, when changing number of channels via
ethtool (ethtool -L) which will cause interface to be reloaded,
it was observed that some packets gets transmitted on old TX
channel/queue id which doesn't really exist after the channel
configuration leads to system crash.

Add a safeguard in the driver by validating queue id through
ndo_select_queue() which is called before the ndo_start_xmit().
Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>