vfio: Check the presence for iommufd callbacks in __vfio_register_dev()

After making the no-DMA drivers (samples/vfio-mdev) providing iommufd
callbacks, __vfio_register_dev() should check the presence of the iommufd
callbacks if CONFIG_IOMMUFD is enabled.

Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Tested-by: Terrence Xu <[email protected]>
Tested-by: Nicolin Chen <[email protected]>
Signed-off-by: Yi Liu <[email protected]>
Acked-by: Alex Williamson <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

0 files changed, 0 insertions, 0 deletions