watchdog:Fix typo in comment

Spelling mistake in comment.

Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Luo Xueqin <luoxueqin@kylinos.cn>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220705153138.29657-1-luoxueqin66@gmail.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>