ath5k: restrict AR5K_TX_QUEUE_ID_DATA_MAX to reflect the [0,3] range

This just matches reality...

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Bob Copeland <me@bobcopeland.com>
diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index 0ee54eb..8a06dbd 100644
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -513,7 +513,7 @@
 	AR5K_TX_QUEUE_ID_NOQCU_DATA	= 0,
 	AR5K_TX_QUEUE_ID_NOQCU_BEACON	= 1,
 	AR5K_TX_QUEUE_ID_DATA_MIN	= 0, /*IEEE80211_TX_QUEUE_DATA0*/
-	AR5K_TX_QUEUE_ID_DATA_MAX	= 4, /*IEEE80211_TX_QUEUE_DATA4*/
+	AR5K_TX_QUEUE_ID_DATA_MAX	= 3, /*IEEE80211_TX_QUEUE_DATA3*/
 	AR5K_TX_QUEUE_ID_DATA_SVP	= 5, /*IEEE80211_TX_QUEUE_SVP - Spectralink Voice Protocol*/
 	AR5K_TX_QUEUE_ID_CAB		= 6, /*IEEE80211_TX_QUEUE_AFTER_BEACON*/
 	AR5K_TX_QUEUE_ID_BEACON		= 7, /*IEEE80211_TX_QUEUE_BEACON*/