iwlwifi: comment that setting driver_data overrides info->control

Using the driver_data area in ieee80211_tx_info which
resides in the CB overrides the info->control field.
Add a comment to prevent mistakes.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
1 file changed