mt76: mt7915: cleanup -Wunused-but-set-variable

Cleanup -Wunused-but-set-variable everywhere in driver.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/mac.c

@@ -1203,7 +1203,6 @@ mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 	count = FIELD_GET(MT_TX_FREE_MSDU_CNT, le16_to_cpu(free->ctrl));
 	for (i = 0; i < count; i++) {
 		u32 msdu, info = le32_to_cpu(free->info[i]);
-		u8 stat;
 
 		/*
 		 * 1'b1: new wcid pair.
@@ -1211,7 +1210,6 @@ mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 		 */
 		if (info & MT_TX_FREE_PAIR) {
 			struct mt7915_sta *msta;
-			struct mt7915_phy *phy;
 			struct mt76_wcid *wcid;
 			u16 idx;
 
@@ -1223,7 +1221,6 @@ mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 				continue;
 
 			msta = container_of(wcid, struct mt7915_sta, wcid);
-			phy = msta->vif->phy;
 			spin_lock_bh(&dev->sta_poll_lock);
 			if (list_empty(&msta->stats_list))
 				list_add_tail(&msta->stats_list, &phy->stats_list);
@@ -1234,8 +1231,6 @@ mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 		}
 
 		msdu = FIELD_GET(MT_TX_FREE_MSDU_ID, info);
-		stat = FIELD_GET(MT_TX_FREE_STATUS, info);
-
 		txwi = mt76_token_release(mdev, msdu, &wake);
 		if (!txwi)
 			continue;
@@ -1374,15 +1369,11 @@ void mt7915_queue_rx_skb(struct mt76_dev *mdev, enum mt76_rxq_id q,
 
 void mt7915_tx_complete_skb(struct mt76_dev *mdev, struct mt76_queue_entry *e)
 {
-	struct mt7915_dev *dev;
-
 	if (!e->txwi) {
 		dev_kfree_skb_any(e->skb);
 		return;
 	}
 
-	dev = container_of(mdev, struct mt7915_dev, mt76);
-
 	/* error path */
 	if (e->skb == DMA_DUMMY_DATA) {
 		struct mt76_txwi_cache *t;