ntdll/tests: Fix test failure on win8.

dlls/ntdll/tests/om.c

@@ -143,7 +143,8 @@ static void test_namespace_pipe(void)
     status = pNtOpenFile(&h, GENERIC_READ, &attr, &iosb, FILE_SHARE_READ|FILE_SHARE_WRITE, FILE_OPEN);
     ok(status == STATUS_OBJECT_PATH_NOT_FOUND ||
        status == STATUS_PIPE_NOT_AVAILABLE ||
-       status == STATUS_OBJECT_NAME_INVALID, /* vista */
+       status == STATUS_OBJECT_NAME_INVALID || /* vista */
+       status == STATUS_OBJECT_NAME_NOT_FOUND, /* win8 */
         "NtOpenFile should have failed with STATUS_OBJECT_PATH_NOT_FOUND got(%08x)\n", status);
 
     pRtlInitUnicodeString(&str, buffer4);