iommufd: Return EOPNOTSUPP for failures due to driver bugs

iommufd: Return EOPNOTSUPP for failures due to driver bugs

It's more accurate to report EOPNOTSUPP when an ioctl failed due to driver
bug, since there is nothing wrong with the user space side.

Link: https://patch.msgid.link/r/623bb6f0e8fdd7b9c5745a2f99f280163f9f1f5a.1749882255.git.nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>