message: free the mpi comm when bp4writer calls DoClose()
diff: @@ -214,12 +214,12 @@ void BP4FileWriter::DoClose(const int transportIndex)
  PerformPuts();
  /*Lipeng*/
  - DoFlush(true, transportIndex);
  + DoFlush(false, transportIndex);
  /*Lipeng*/
  if (m_BP4Serializer.m_CollectiveMetadata &&
  m_FileDataManager.AllTransportsClosed())
  {
  - WriteCollectiveMetadataFile(true);
  + WriteCollectiveMetadataFile(false);
  }
  }
  @@ -245,6 +245,8 @@ void BP4FileWriter::DoClose(const int transportIndex)
  {
  WriteProfilingJSONFile();
  }
  +
  + m_BP4Serializer.m_Aggregator.Close();
  }
  void BP4FileWriter::WriteProfilingJSONFile()
  