watchdog: wdat_wdt: Stop watchdog when uninstalling module

Test shows that wachdog still reboots machine after the module
is removed. Use watchdog_stop_on_unregister to stop the watchdog
on removing.

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
eviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1650984810-6247-4-git-send-email-liuxp11@chinatelecom.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Author: liuxp11

drivers/watchdog/wdat_wdt.c

@@ -463,6 +463,7 @@ static int wdat_wdt_probe(struct platform_device *pdev)
 
 	watchdog_set_nowayout(&wdat->wdd, nowayout);
 	watchdog_stop_on_reboot(&wdat->wdd);
+	watchdog_stop_on_unregister(&wdat->wdd);
 	return devm_watchdog_register_device(dev, &wdat->wdd);
 }