ACPI: thermal: Use thermal_zone_device()

In order to get the device associated with the thermal zone, let's use
the wrapper thermal_zone_device() instead of accessing directly the
content of the thermal zone device structure.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[ rjw: Subject adjustment, removal of trailing white space ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/thermal.c

@@ -789,6 +789,7 @@ static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 
 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 {
+	struct device *tzdev;
 	int trips = 0;
 	int result;
 	acpi_status status;
@@ -820,12 +821,14 @@ static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 	if (IS_ERR(tz->thermal_zone))
 		return -ENODEV;
 
+	tzdev = thermal_zone_device(tz->thermal_zone);
+
 	result = sysfs_create_link(&tz->device->dev.kobj,
-				   &tz->thermal_zone->device.kobj, "thermal_zone");
+				   &tzdev->kobj, "thermal_zone");
 	if (result)
 		goto unregister_tzd;
 
-	result = sysfs_create_link(&tz->thermal_zone->device.kobj,
+	result = sysfs_create_link(&tzdev->kobj,
 				   &tz->device->dev.kobj, "device");
 	if (result)
 		goto remove_tz_link;
@@ -849,7 +852,7 @@ static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 acpi_bus_detach:
 	acpi_bus_detach_private_data(tz->device->handle);
 remove_dev_link:
-	sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
+	sysfs_remove_link(&tzdev->kobj, "device");
 remove_tz_link:
 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 unregister_tzd:
@@ -860,8 +863,10 @@ static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 
 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
 {
+	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
+
 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
-	sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
+	sysfs_remove_link(&tzdev->kobj, "device");
 	thermal_zone_device_unregister(tz->thermal_zone);
 	tz->thermal_zone = NULL;
 	acpi_bus_detach_private_data(tz->device->handle);