IOR with '--hdf5.showHints' will trigger unsupported 'optional' callback

I can't yet figure out what IOR-4.0 is trying to do with the VOL when I run a benchmark with '--hdf5.showHints'.

For example, with HDF5-1.14.6 and the VOL-DAOS, this IOR run will succeeed:

ior --mpiio.showHints -c -a HDF5 -b 1000000 -t 1000000 -o /tmp/${DAOS_POOL}/${DAOS_CONT}/ior-hdf5-vol.h5

But if I merely ask for --hdf5.showHints like this:

ior --mpiio.showHints --hdf5.showHints -c -a HDF5 -b 1000000 -t 1000000 -o /tmp/${DAOS_POOL}/${DAOS_CONT}/ior-hdf5-vol.h5

I will get the following error backtrace:

```
HDF5-DIAG: Error detected in HDF5 (1.14.6) MPI-process 0:
#000: /home/robl/src/hdf5/src/H5F.c line 453 in H5Fget_vfd_handle(): unable to get VFD handle
major: File accessibility
minor: Can't get value
#001: /home/robl/src/hdf5/src/H5VLcallback.c line 4010 in H5VL_file_optional(): file optional failed
major: Virtual Object Layer
minor: Can't operate on object
#002: /home/robl/src/hdf5/src/H5VLcallback.c line 3975 in H5VL__file_optional(): VOL connector has no 'file optional' method
major: Virtual Object Layer
minor: Feature is unsupported
```

IOR it appears is simply trying to create the file:
```
(gdb) where
#0 H5VL__file_optional (obj=, cls=0x3d7f820, args=0x7ffffffe5fa0, dxpl_id=792633534417207304, req=0x0) at /home/robl/src/hdf5/src/H5VLcallback.c:3974
#1 H5VL_file_optional (vol_obj=0x4060800, args=args@entry=0x7ffffffe5fa0, dxpl_id=792633534417207304, req=req@entry=0x0) at /home/robl/src/hdf5/src/H5VLcallback.c:4009
#2 0x000015555520e087 in H5Fget_vfd_handle (file_id=72057594037927936, fapl_id=792633534417207320, file_handle=) at /home/robl/src/hdf5/src/H5F.c:452
#3 0x0000000000409f73 in HDF5_Open (testFileName=0x7ffffffe7f30 "/tmp/radix-io/ior-hdf5/ior-hdf5-vol.h5", flags=50, param=0x3d32290) at ../../src/aiori-HDF5.c:327
#4 0x0000000000409803 in HDF5_Create (testFileName=0x7ffffffe7f30 "/tmp/radix-io/ior-hdf5/ior-hdf5-vol.h5", flags=50, param=0x3d32290) at ../../src/aiori-HDF5.c:212
#5 0x0000000000418a7e in TestIoSys (test=0x43c9190) at ../../src/ior.c:1249
#6 0x0000000000419f51 in ior_main (argc=12, argv=0x7ffffffe8ac8) at ../../src/ior.c:229
#7 0x0000000000407f02 in main (argc=12, argv=0x7ffffffe8ac8) at ../../src/ior-main.c:5
```
I don't know why showHints is causing it to ask for an unsupported operation