iommu: Use dev_iommu_ops() for probe_finalize

The ->probe_finalize hook only runs after ->probe_device succeeds,
so we can move that over to the new dev_iommu_ops() as well.
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/5fe4b0ce22f676f435d332f2b2828dc7ef848a19.1655822151.git.robin.murphy@arm.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/iommu.c

@@ -272,7 +272,7 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
 
 int iommu_probe_device(struct device *dev)
 {
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops;
 	struct iommu_group *group;
 	int ret;
 
@@ -313,6 +313,7 @@ int iommu_probe_device(struct device *dev)
 	mutex_unlock(&group->mutex);
 	iommu_group_put(group);
 
+	ops = dev_iommu_ops(dev);
 	if (ops->probe_finalize)
 		ops->probe_finalize(dev);