mt76: mt7921: do not update pm states in case of error

Do not update pm stats if mt7921e_mcu_fw_pmctrl routine returns an
error.

Fixes: 36873246 ("mt76: mt7921: add awake and doze time accounting")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

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

@@ -102,7 +102,7 @@ int mt7921e_mcu_fw_pmctrl(struct mt7921_dev *dev)
 {
 	struct mt76_phy *mphy = &dev->mt76.phy;
 	struct mt76_connac_pm *pm = &dev->pm;
-	int i, err = 0;
+	int i;
 
 	for (i = 0; i < MT7921_DRV_OWN_RETRY_COUNT; i++) {
 		mt76_wr(dev, MT_CONN_ON_LPCTL, PCIE_LPCR_HOST_SET_OWN);
@@ -114,12 +114,12 @@ int mt7921e_mcu_fw_pmctrl(struct mt7921_dev *dev)
 	if (i == MT7921_DRV_OWN_RETRY_COUNT) {
 		dev_err(dev->mt76.dev, "firmware own failed\n");
 		clear_bit(MT76_STATE_PM, &mphy->state);
-		err = -EIO;
+		return -EIO;
 	}
 
 	pm->stats.last_doze_event = jiffies;
 	pm->stats.awake_time += pm->stats.last_doze_event -
 				pm->stats.last_wake_event;
 
-	return err;
+	return 0;
 }