iommu/vt-d: Unlink device if failed to add to group

If the device fails to be added to the group, make sure to unlink the
reference before returning.

Signed-off-by: Jon Derrick <[e-mail]>
Fixes: 39ab9555c2411 ("iommu: Add sysfs bindings for struct iommu_device")
Acked-by: Lu Baolu <[e-mail]>
Signed-off-by: Joerg Roedel <[e-mail]>

drivers/iommu/intel-iommu.c

···
 
 	group = iommu_group_get_for_dev(dev);
 
-	if (IS_ERR(group))
-		return PTR_ERR(group);
+	if (IS_ERR(group)) {
+		ret = PTR_ERR(group);
+		goto unlink;
+	}
 
 	iommu_group_put(group);
 
···
 				if (!get_private_domain_for_dev(dev)) {
 					dev_warn(dev,
 						 "Failed to get a private domain.\n");
-					return -ENOMEM;
+					ret = -ENOMEM;
+					goto unlink;
 				}
 
 				dev_info(dev,
···
 	}
 
 	return 0;
+
+unlink:
+	iommu_device_unlink(&iommu->iommu, dev);
+	return ret;
 }
 
 static void intel_iommu_remove_device(struct device *dev)