ath9k_hw: clean up tx completion interrupt handling

TXQ_FLAG_TXOKINT_ENABLE and TXQ_FLAG_TXERRINT_ENABLE are always set and
used together, and they share the same bitmask in enum ath9k_tx_queue_flags.
Simplify the code that tests for these flags.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 5faec1e..c6b93f6 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1355,8 +1355,7 @@
 	 * based intr on the EOSP frames.
 	 */
 	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
-		qi.tqi_qflags = TXQ_FLAG_TXOKINT_ENABLE |
-				TXQ_FLAG_TXERRINT_ENABLE;
+		qi.tqi_qflags = TXQ_FLAG_TXINT_ENABLE;
 	} else {
 		if (qtype == ATH9K_TX_QUEUE_UAPSD)
 			qi.tqi_qflags = TXQ_FLAG_TXDESCINT_ENABLE;