message: Fix an unused variable warning. NFC
diff: @@ -44,8 +44,10 @@ const char *StopInfoMachException::GetDescription() {
  const char *subcode_label = "subcode";
  const char *subcode_desc = NULL;
  +#if defined(__APPLE__)
  char code_desc_buf[32];
  char subcode_desc_buf[32];
  +#endif
  switch (m_value) {
  case 1: // EXC_BAD_ACCESS
  