ath9k: fix missed error codes in the tx status check

My previous change added in:

 commit 815833e7ecf0b9a017315cae6aef4d7cd9517681
    ath9k: fix tx status reporting

was not checking all possible tx error conditions. This could possibly
lead to throughput issues due to slow rate control adaption or missed
retransmissions of failed A-MPDU frames.

This patch adds a mask for all possible error conditions and uses it
in the xmit ok check.

Cc: stable@kernel.org
Reported-by: Björn Smedman <bjorn.smedman@venatech.se>
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 1e813bb..fa12b90 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -2072,7 +2072,7 @@
 				&txq->axq_q, lastbf->list.prev);
 
 		txq->axq_depth--;
-		txok = !(ds->ds_txstat.ts_status & ATH9K_TXERR_FILT);
+		txok = !(ds->ds_txstat.ts_status & ATH9K_TXERR_MASK);
 		txq->axq_tx_inprogress = false;
 		spin_unlock_bh(&txq->axq_lock);