[media] v4l2-dev.c: Move video_put() after debug printk

It is possible that video_put() releases video_device struct,
provoking a panic when debug printk wants to get video_device node name.

Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>