hdf5_ep

[svn-r4396] Purpose:
    bug fix
Description:
    H5FD_mpio_flush() would try to file seek negative if the
    file->eoa is 0 (e.g., doing mpio on the raw-file of the
    split file driver).  Put in a code to catch this case
    by returning succeed immediately.
Platforms tested:
    modi4(pp)