ipmi/watchdog: use strscpy() to instead of strncpy()

Xu Panda <xu.panda@zte.com.cn>

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL terminated strings.

Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Message-Id: <202212051936400309332@zte.com.cn>
Signed-off-by: Corey Minyard <cminyard@mvista.com>