mac80211: use IEEE80211_NUM_ACS

When comparing hw->queues to determine if the
device is QoS capable, use IEEE80211_NUM_ACS
instead of just 4.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index b35d319..14a01c8 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1928,7 +1928,7 @@
 		wme_sta = true;
 
 	/* receiver and we are QoS enabled, use a QoS type frame */
-	if (wme_sta && local->hw.queues >= 4) {
+	if (wme_sta && local->hw.queues >= IEEE80211_NUM_ACS) {
 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
 		hdrlen += 2;
 	}