[media] media: davinci: vpbe: use helpers provided by core if streaming is started

this patch uses vb2_is_busy() helper to check if streaming is
actually started, instead of driver managing it.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2 files changed