virtio_ccw: support non-legacy balloon devices

As of last patch, virtio_device_is_legacy_only is always false,
drop the test from virtio ccw.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (slight reword)

drivers/s390/kvm/virtio_ccw.c

@@ -1201,13 +1201,9 @@ static int virtio_ccw_online(struct ccw_device *cdev)
 	vcdev->vdev.id.vendor = cdev->id.cu_type;
 	vcdev->vdev.id.device = cdev->id.cu_model;
 
-	if (virtio_device_is_legacy_only(vcdev->vdev.id)) {
-		vcdev->revision = 0;
-	} else {
 	ret = virtio_ccw_set_transport_rev(vcdev);
 	if (ret)
 		goto out_free;
-	}
 
 	ret = register_virtio_device(&vcdev->vdev);
 	if (ret) {