mt76: mt7921: get rid of monitor_vif

Remove monitor_vif pointer from mt7921 since it is just a leftover of
initial porting.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7921/main.c

@@ -243,10 +243,6 @@ static int mt7921_add_interface(struct ieee80211_hw *hw,
 
 	mt7921_mutex_acquire(dev);
 
-	if (vif->type == NL80211_IFTYPE_MONITOR &&
-	    is_zero_ether_addr(vif->addr))
-		phy->monitor_vif = vif;
-
 	mvif->mt76.idx = ffs(~dev->mt76.vif_mask) - 1;
 	if (mvif->mt76.idx >= MT7921_MAX_INTERFACES) {
 		ret = -ENOSPC;
@@ -306,9 +302,6 @@ static void mt7921_remove_interface(struct ieee80211_hw *hw,
 	struct mt7921_phy *phy = mt7921_hw_phy(hw);
 	int idx = msta->wcid.idx;
 
-	if (vif == phy->monitor_vif)
-		phy->monitor_vif = NULL;
-
 	mt7921_mutex_acquire(dev);
 	mt76_connac_free_pending_tx_skbs(&dev->pm, &msta->wcid);
 	mt76_connac_mcu_uni_add_dev(&dev->mphy, vif, &mvif->sta.wcid, false);

drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h

@@ -126,8 +126,6 @@ struct mt7921_phy {
 
 	struct ieee80211_sband_iftype_data iftype[2][NUM_NL80211_IFTYPES];
 
-	struct ieee80211_vif *monitor_vif;
-
 	u32 rxfilter;
 	u64 omac_mask;