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 <l.majewski@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 43b9070..8567929 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -928,7 +928,7 @@
 	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;
@@ -945,7 +945,9 @@
 	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;