LU-16520 build: Move strscpy to libcfs common header

LU-16520 build: Move strscpy to libcfs common header

Ensure strscpy is available to lustre

Lustre-change: https://review.whamcloud.com/49863
Lustre-commit: 7fe7f4ca06b9c8d128f7ba36988e36f8141ed53d

Test-Parameters: trivial
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I0c3673c2aa7e6b61671521a8cabde8a364f7f6f8
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56766
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>