mt76: fix possible out-of-bound access in mt7615_fill_txs/mt7603_fill_txs

Fix possible out-of-bound access of status rates array in
mt7615_fill_txs/mt7603_fill_txs routines

Fixes: c5211e99 ("mt76: mt7603: rework and fix tx status reporting")
Fixes: 4af81f02 ("mt76: mt7615: sync with mt7603 rate control changes")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7603/mac.c

@@ -1136,8 +1136,10 @@ mt7603_fill_txs(struct mt7603_dev *dev, struct mt7603_sta *sta,
 		if (idx && (cur_rate->idx != info->status.rates[i].idx ||
 			    cur_rate->flags != info->status.rates[i].flags)) {
 			i++;
-			if (i == ARRAY_SIZE(info->status.rates))
+			if (i == ARRAY_SIZE(info->status.rates)) {
+				i--;
 				break;
+			}
 
 			info->status.rates[i] = *cur_rate;
 			info->status.rates[i].count = 0;

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

@@ -1039,8 +1039,10 @@ static bool mt7615_fill_txs(struct mt7615_dev *dev, struct mt7615_sta *sta,
 		if (idx && (cur_rate->idx != info->status.rates[i].idx ||
 			    cur_rate->flags != info->status.rates[i].flags)) {
 			i++;
-			if (i == ARRAY_SIZE(info->status.rates))
+			if (i == ARRAY_SIZE(info->status.rates)) {
+				i--;
 				break;
+			}
 
 			info->status.rates[i] = *cur_rate;
 			info->status.rates[i].count = 0;