wifi: ath9k: remove redundant assignment to variable ret

The variable ret is being assigned a value but it isn't being
read afterwards. The assignment is redundant and so ret can be
removed.

Cleans up clang scan build warning:
warning: Although the value stored to 'ret' is used in the
enclosing expression, the value is never actually read from
'ret' [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240116155452.2315351-1-colin.i.king@gmail.com

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

@@ -369,12 +369,11 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
 	struct list_head bf_head;
 	struct ath_tx_status ts;
 	struct ath_frame_info *fi;
-	int ret;
 
 	memset(&ts, 0, sizeof(ts));
 	INIT_LIST_HEAD(&bf_head);
 
-	while ((ret = ath_tid_dequeue(tid, &skb)) == 0) {
+	while (ath_tid_dequeue(tid, &skb) == 0) {
 		fi = get_frame_info(skb);
 		bf = fi->bf;