mt76: check for pending reset before attempting to schedule tx

The check within mt76_txq_send_burst is not enough, as it happens after
a first frame has already been queued up

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mediatek/mt76/tx.c

@@ -385,6 +385,10 @@ restart:
 		bool empty = false;
 		int cur;
 
+		if (test_bit(MT76_SCANNING, &dev->state) ||
+		    test_bit(MT76_RESET, &dev->state))
+			return -EBUSY;
+
 		mtxq = list_first_entry(&hwq->swq, struct mt76_txq, list);
 		if (mtxq->send_bar && mtxq->aggr) {
 			struct ieee80211_txq *txq = mtxq_to_txq(mtxq);