[media] vpif_capture.c: v4l2_device_register() is called too late in vpif_probe()

[media] vpif_capture.c: v4l2_device_register() is called too late in vpif_probe()

The function v4l2_device_register() is called too late in vpif_probe().
This meant that vpif_obj.v4l2_dev is accessed before it is initialized
which caused a crash.

This used to work in the past, but video_register_device() is now actually
using the v4l2_dev pointer.

Note that vpif_display.c doesn't have this bug, there v4l2_device_register()
is called at the beginning of vpif_probe.

Signed-off-by: Georgios Plakaris <gplakari@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Manjunath Hadli <Manjunath.hadli@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>