iwl4965: Remove redundant code in iwl4965_tx_cmd

This function removes redundant code in iwl4965_tx_cmd
function, leftovers of previous design.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>