qlcnic: Fix tx timeout.

o __qlcnic_down call's netif_tx_disable which in turn stops
  all the TX queues, corresponding start queue was missing in
  __qlcnic_up which was leading to tx timeout.
o The commit b84caae4
  (qlcnic: Fix usage of netif_tx_{wake, stop} api during link change.)
  exposed this issue.

Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>