rdflib.c: add back timestamp size to header in library creation.

Commit 8dc965347 removed writing of the timestamp size to library
header. (Accidentally, I guess??) The attached patch adds it back.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>

rdoff/rdflib.c

@@ -181,6 +181,8 @@ int main(int argc, char **argv)
         nasm_write(sig_modname, strlen(sig_modname) + 1, fp);
         nasm_write(rdl_signature, strlen(rdl_signature), fp);
 	t = time(NULL);
+        l = sizeof(t);
+        fwriteint32_t(l, fp);
         fwriteint32_t(t, fp);
         fclose(fp);
         break;