cpio: dont use UNUSED_PARAM, it exists only in 1.11.1

diff --git a/archival/cpio.c b/archival/cpio.c
index bf442d7..6a8ee67 100644
--- a/archival/cpio.c
+++ b/archival/cpio.c
@@ -246,7 +246,7 @@
  */
 
 int cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int cpio_main(int argc UNUSED_PARAM, char **argv)
+int cpio_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
 	archive_handle_t *archive_handle;
 	char *cpio_filename;