vfio/ap_ops: Add missed vfio_uninit_group_dev()

vfio/ap_ops: Add missed vfio_uninit_group_dev()

Without this call an xarray entry is leaked when the vfio_ap device is
unprobed. It was missed when the below patch was rebased across the
dev_set patch. Keep the remove function in the same order as the error
unwind in probe.

Fixes: eb0feefd4c02 ("vfio/ap_ops: Convert to use vfio_register_group_dev()")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Link: https://lore.kernel.org/r/0-v3-f9b50340cdbb+e4-ap_uninit_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>