iwlwifi: remove TX hex debug

Tracing is much better for this, so
remove the hex printk debug for the
TX command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>