mac80211: remove ieee80211_tx_info from rate_control_apply_mask signature

Remove unnecessary ieee80211_tx_info pointer from rate_control_apply_mask
signature. rate_control_apply_mask() will be used to define a ratemask in
rate_control_set_rates() for station rate table

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>