thermal:core:fix: Check return code of the ->get_max_state() callback

The return code from ->get_max_state() callback was not checked during
binding cooling device to thermal zone device.

Signed-off-by: Lukasz Majewski <[e-mail]>
Signed-off-by: Eduardo Valentin <[e-mail]>

drivers/thermal/thermal_core.c

···
 	struct thermal_zone_device *pos1;
 	struct thermal_cooling_device *pos2;
 	unsigned long max_state;
-	int result;
+	int result, ret;
 
 	if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
 		return -EINVAL;
···
 	if (tz != pos1 || cdev != pos2)
 		return -EINVAL;
 
-	cdev->ops->get_max_state(cdev, &max_state);
+	ret = cdev->ops->get_max_state(cdev, &max_state);
+	if (ret)
+		return ret;
 
 	/* lower default 0, upper default max_state */
 	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;