ath9k: avoid aggregation for VO traffic

This should help with latency issues which can happen when
using aggregation.

Cc: Matt Smith <matt.smith@atheros.com>
Cc: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/rc.c

@@ -1363,7 +1363,8 @@ static void ath_tx_status(void *priv, struct ieee80211_supported_band *sband,
 	/* Check if aggregation has to be enabled for this tid */
 	if (conf_is_ht(&sc->hw->conf) &&
 	    !(skb->protocol == cpu_to_be16(ETH_P_PAE))) {
-		if (ieee80211_is_data_qos(fc)) {
+		if (ieee80211_is_data_qos(fc) &&
+		    skb_get_queue_mapping(skb) != IEEE80211_AC_VO) {
 			u8 *qc, tid;
 			struct ath_node *an;