Fix the following coccicheck warning:

drivers/watchdog/riowd.c:144:2-3: Unneeded semicolon
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200428063333.2743-1-yanaijie@huawei.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>