hdf5_ep

Merge pull request #2094 in HDFFV/hdf5 from ~KMU/hdf5:bugfix/unused to develop

* commit '145ef3ceee20c28a443bd11507c58858bea3f889':
  more cleanup
  change it back
  pick up missing piece
  fix unused related warnings
  removed unused parameter
  more fix and address comments
  remove unsed var,function,macro, etc