params: Replace deprecated strcpy() with strscpy() and memcpy()

strcpy() is deprecated; use strscpy() and memcpy() instead.

In param_set_copystring(), we can safely use memcpy() because we already
know the length of the source string 'val' and that it is guaranteed to
be NUL-terminated within the first 'kps->maxlen' bytes.

Link: https://github.com/KSPP/linux/issues/88


Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Link: https://lore.kernel.org/r/20250813132200.184064-2-thorsten.blum@linux.dev


Signed-off-by: Daniel Gomez <da.gomez@samsung.com>