[media] drivers: media: platform: vivid: Fix possible null derefrence
[media] drivers: media: platform: vivid: Fix possible null derefrence

Check for dev_fmt being null before derefrencing it, to assign it
to planes.

Found using Coccinelle.

Signed-off-by: Tapasweni Pathak <3b69268f7ace5bdf0735d0c2203b969d339216e4@gmail.com>
Acked-by: Julia Lawall <018ee4f95fc49739477deedb13d2cd210889e607@lip6.fr>
Signed-off-by: Hans Verkuil <3a513708f73c27e7d36ebc496aa41dad6a3153ea@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@osg.samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs