media: v4l: subdev: Copy argument back to user also for S_ROUTING

As the user needs to know what went wrong for S_ROUTING, copy array
arguments back to the user.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Julien Massot <julien.massot@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>