vfio: use the new pci_dev_trylock() helper to simplify try lock

Use the new pci_dev_trylock() helper to simplify our locking.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20210623022824.308041-3-mcgrof@kernel.org


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>