mac80211: use helper function to access ieee802_1d_to_ac[]

cleanup patch to make use of ieee80211_ac_from_tid() to retrieve ac from
ieee802_1d_to_ac[]

Signed-off-by: Amadeusz Sławiński <amadeusz.slawinski@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 986de09..ba8d7db 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1414,7 +1414,7 @@ void ieee80211_txq_init(struct ieee80211_sub_if_data *sdata,
 		txqi->txq.sta = &sta->sta;
 		sta->sta.txq[tid] = &txqi->txq;
 		txqi->txq.tid = tid;
-		txqi->txq.ac = ieee802_1d_to_ac[tid & 7];
+		txqi->txq.ac = ieee80211_ac_from_tid(tid);
 	} else {
 		sdata->vif.txq = &txqi->txq;
 		txqi->txq.tid = 0;
@@ -4659,7 +4659,7 @@ void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
 				 struct sk_buff *skb, int tid,
 				 enum nl80211_band band)
 {
-	int ac = ieee802_1d_to_ac[tid & 7];
+	int ac = ieee80211_ac_from_tid(tid);
 
 	skb_reset_mac_header(skb);
 	skb_set_queue_mapping(skb, ac);