message: fix lib_io_record_reader_writer_test timeout
diff: @@ -191,7 +191,7 @@ Status ZlibOutputBuffer::Append(StringPiece data) {
  }
  Status ZlibOutputBuffer::Flush() {
  - TF_RETURN_IF_ERROR(DeflateBuffered(Z_FULL_FLUSH));
  + TF_RETURN_IF_ERROR(DeflateBuffered(Z_PARTIAL_FLUSH));
  TF_RETURN_IF_ERROR(FlushOutputBufferToFile());
  return file_->Flush();
  }
  