thermal/core/power allocator: Use the lockless __thermal_cdev_update() function

Use the new helper function and avoid unnecessery second lock/unlock,
which was present in old approach with thermal_cdev_update().
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210422153624.6074-4-lukasz.luba@arm.com

drivers/thermal/gov_power_allocator.c

@@ -301,9 +301,8 @@ power_actor_set_power(struct thermal_cooling_device *cdev,
 
 	instance->target = clamp_val(state, instance->lower, instance->upper);
 	mutex_lock(&cdev->lock);
-	cdev->updated = false;
+	__thermal_cdev_update(cdev);
 	mutex_unlock(&cdev->lock);
-	thermal_cdev_update(cdev);
 
 	return 0;
 }