mac80211: remove tx status ampdu_ack_map

There's a single use of this struct member, but
as it is write-only it clearly not necessary.
Thus we can free up some space here, even if we
don't need it right now it seems pointless to
carry around the variable.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-agn-tx.c

@@ -1252,7 +1252,6 @@ static int iwlagn_tx_status_reply_compressed_ba(struct iwl_priv *priv,
 	info->flags |= IEEE80211_TX_STAT_ACK;
 	info->flags |= IEEE80211_TX_STAT_AMPDU;
 	info->status.ampdu_ack_len = successes;
-	info->status.ampdu_ack_map = bitmap;
 	info->status.ampdu_len = agg->frame_count;
 	iwlagn_hwrate_to_tx_control(priv, agg->rate_n_flags, info);
 

include/net/mac80211.h

@@ -412,8 +412,6 @@ struct ieee80211_tx_rate {
  * @driver_data: array of driver_data pointers
  * @ampdu_ack_len: number of acked aggregated frames.
  * 	relevant only if IEEE80211_TX_STAT_AMPDU was set.
- * @ampdu_ack_map: block ack bit map for the aggregation.
- * 	relevant only if IEEE80211_TX_STAT_AMPDU was set.
  * @ampdu_len: number of aggregated frames.
  * 	relevant only if IEEE80211_TX_STAT_AMPDU was set.
  * @ack_signal: signal strength of the ACK frame
@@ -448,10 +446,9 @@ struct ieee80211_tx_info {
 		struct {
 			struct ieee80211_tx_rate rates[IEEE80211_TX_MAX_RATES];
 			u8 ampdu_ack_len;
-			u64 ampdu_ack_map;
 			int ack_signal;
 			u8 ampdu_len;
-			/* 7 bytes free */
+			/* 15 bytes free */
 		} status;
 		struct {
 			struct ieee80211_tx_rate driver_rates[