virtio-ccw: wire up ->bus_name callback

Return the bus id of the ccw proxy device. This makes 'ethtool -i'
show a more useful value than 'virtio' in the bus-info field.
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/s390/virtio/virtio_ccw.c

@@ -975,6 +975,13 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 	kfree(ccw);
 }
 
+static const char *virtio_ccw_bus_name(struct virtio_device *vdev)
+{
+	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
+
+	return dev_name(&vcdev->cdev->dev);
+}
+
 static const struct virtio_config_ops virtio_ccw_config_ops = {
 	.get_features = virtio_ccw_get_features,
 	.finalize_features = virtio_ccw_finalize_features,
@@ -985,6 +992,7 @@ static const struct virtio_config_ops virtio_ccw_config_ops = {
 	.reset = virtio_ccw_reset,
 	.find_vqs = virtio_ccw_find_vqs,
 	.del_vqs = virtio_ccw_del_vqs,
+	.bus_name = virtio_ccw_bus_name,
 };