qlcnic: Validate Tx queue only for 82xx adapters.

o validate Tx queue only in case of adapters which supports
  multi Tx queue.

  This patch is to fix regression introduced in commit
  aa4a1f7df7cbb98797c9f4edfde3c726e2b3841f
  "qlcnic: Enable Tx queue changes using ethtool for 82xx Series adapter"

Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>