iommufd: Simplify iommufd_device_remove_vdev()

Peiyang reports that this function indirectly includes a fault injection
point through iommufd_get_object() that was intended to cover the uAPI use
of object IDs, not in places like this that cannot fail.

On deeper inspection this can be written using a dedicated helper to
obtain a users refcount relying entirely on the xa locking instead of
going through the whole get/put scheme. The new helper doesn't need the
fault injection point.

Fixes: 850f14f5b919 ("iommufd: Destroy vdevice on idevice destroy")
Link: https://patch.msgid.link/r/0-v1-719003d53a5b+38b-iommufd_fault_inj_vdev_jgg@nvidia.com
Reported-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Closes: https://lore.kernel.org/r/870BB9ADBBEDDD1A+37c5bfab-ad32-4fc5-a302-57c81a8432b5@smail.nju.edu.cn
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

0 files changed, 0 insertions, 0 deletions