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>

drivers/net/wireless/ath/ath5k/ath5k.h

@@ -513,7 +513,7 @@ enum ath5k_tx_queue_id {
 	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*/