ia64: mca: use strscpy() is more robust and safer

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

Link: https://lkml.kernel.org/r/20220930061950.288290-1-xu.xin16@zte.com.cn
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Cc: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>