[media] media: sh-vou: fix compiler warnings

sh-vou causes several "may be used uninitialized" warnings. Even though
they all are purely theoretical, it is better to fix them.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>