Thermal_Framework-Fix_crash_during_hwmon_unregister

This patch fixes the following bug:
The thermal framework creates a temp*_crit interface, only when
the get_crit_temp pointer is defined. But during the _unregister_
path, without checking for the function definition, it is trying to
remove the temp*_crit interface.
Signed-off-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/thermal/thermal_sys.c

@@ -560,7 +560,8 @@ thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
 
 	tz->hwmon = NULL;
 	device_remove_file(hwmon->device, &tz->temp_input.attr);
-	device_remove_file(hwmon->device, &tz->temp_crit.attr);
+	if (tz->ops->get_crit_temp)
+		device_remove_file(hwmon->device, &tz->temp_crit.attr);
 
 	mutex_lock(&thermal_list_lock);
 	list_del(&tz->hwmon_node);