thermal/core: Correct function name thermal_zone_device_unregister()

Fix the following make W=1 kernel build warning:

  drivers/thermal/thermal_core.c:1376: warning: expecting prototype for thermal_device_unregister(). Prototype was for thermal_zone_device_unregister() instead
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210517051020.3463536-1-yangyingliang@huawei.com

drivers/thermal/thermal_core.c

@@ -1369,7 +1369,7 @@ thermal_zone_device_register(const char *type, int trips, int mask,
 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
 
 /**
- * thermal_device_unregister - removes the registered thermal zone device
+ * thermal_zone_device_unregister - removes the registered thermal zone device
  * @tz: the thermal zone device to remove
  */
 void thermal_zone_device_unregister(struct thermal_zone_device *tz)