scsi: elx: libefc: Replace deprecated strncpy() with strscpy_pad()/memcpy()

strncpy() is deprecated for use on NUL-terminated destination strings [1]
and as such we should prefer more robust and less ambiguous string
interfaces.

To keep node->current_state_name and node->prev_state_name NUL-padded and
NUL-terminated let's use strscpy_pad() as this implicitly provides both.

For the swap between the two, a simple memcpy() will suffice.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90


Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20231026-strncpy-drivers-scsi-elx-libefc-efc_node-h-v2-1-5c083d0c13f4@google.com


Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>