wifi: mt76: mt7915: unlock on error in mt7915_thermal_temp_store()

Drop the lock before returning -EINVAL.

Fixes: ecaccdae ("wifi: mt76: mt7915: rework mt7915_thermal_temp_store()")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

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

@@ -89,6 +89,7 @@ static ssize_t mt7915_thermal_temp_store(struct device *dev,
 	     val < phy->throttle_temp[MT7915_CRIT_TEMP_IDX])) {
 		dev_err(phy->dev->mt76.dev,
 			"temp1_max shall be greater than temp1_crit.");
+		mutex_unlock(&phy->dev->mt76.mutex);
 		return -EINVAL;
 	}