Remove unused variable to fix warning

Utilities/cmlibarchive/libarchive/archive_read_support_format_iso9660.c

@@ -477,9 +477,10 @@ archive_read_format_iso9660_options(struct archive_read *a,
 }
 
 static int
-isVDSetTerminator(struct iso9660 *, const unsigned char *h)
+isVDSetTerminator(struct iso9660 *iso9660, const unsigned char *h)
 {
     int i;
+  (void)iso9660;
 
     /* Type of the Volume Descriptor Set Terminator must be 255. */
     if (h[0] != 255)