vfio/pci: Pass an error object to vfio_populate_device

vfio/pci: Pass an error object to vfio_populate_device

Pass an error object to prepare for migration to VFIO-PCI realize.
The returned value will be removed later on.

The case where error recovery cannot be enabled is not converted into
an error object but directly reported through error_report, as before.
Populating an error instead would cause the future realize function to
fail, which is not wanted.

Signed-off-by: Eric Auger <[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>