iommu: Propagate return value in ->attach_dev callback functions

The mtk_iommu and virtio drivers have places in the ->attach_dev callback
functions that return hardcode errnos instead of the returned values, but
callers of these ->attach_dv callback functions may care. Propagate them
directly without the extra conversions.

Link: https://lore.kernel.org/r/ca8c5a447b87002334f83325f28823008b4ce420.1666042873.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/iommu/mtk_iommu.c

@@ -668,7 +668,7 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
 		ret = mtk_iommu_domain_finalise(dom, frstdata, region_id);
 		if (ret) {
 			mutex_unlock(&dom->mutex);
-			return -ENODEV;
+			return ret;
 		}
 		dom->bank = &data->bank[bankid];
 	}

drivers/iommu/virtio-iommu.c

@@ -697,7 +697,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev,
 		if (ret) {
 			ida_free(&viommu->domain_ids, vdomain->id);
 			vdomain->viommu = NULL;
-			return -EOPNOTSUPP;
+			return ret;
 		}
 	}