hdf5_msb

A fix in the cleaning up code for datatype when datatype initialization via H5D__init_type() fails.
This is triggered by the tests for revised references when the libver bounds setting does not allow version
4 datatype message to be created.  The test failure is abort core dumped.
This is due to the datatype initialization fails before the datatype ID is registered.
The datatype cleanup code should provide for the above situation.
The code to fix the problem is the same as what is done in H5D__open_oid().