[media] adv7180: Remove duplicate unregister call

This driver moved over to v4l2_async_unregister_subdev()
but still retained a call to v4l2_unregister_subdev(). Remove.

Signed-off-by: Ian Molton <ian.molton@codethink.co.uk>
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/i2c/adv7180.c

@@ -663,7 +663,6 @@ static int adv7180_remove(struct i2c_client *client)
 	if (state->irq > 0)
 		free_irq(client->irq, state);
 
-	v4l2_device_unregister_subdev(sd);
 	adv7180_exit_controls(state);
 	mutex_destroy(&state->mutex);
 	return 0;