wifi: ath9k: avoid using uninitialized array

In 'ath_tx_count_frames()', 'ba' array may be used uninitialized, so
add 'memset()' call similar to one used in 'ath_tx_complete_aggr()'.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230620080855.396851-1-dmantipov@yandex.ru

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

@@ -466,6 +466,8 @@ static void ath_tx_count_frames(struct ath_softc *sc, struct ath_buf *bf,
 	*nframes = 0;
 
 	isaggr = bf_isaggr(bf);
+	memset(ba, 0, WME_BA_BMP_SIZE >> 3);
+
 	if (isaggr) {
 		seq_st = ts->ts_seqnum;
 		memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3);