[media] cpia2: fix typo in variable initialisation

Currently 'fh' initialises to whatever happens to be on stack. This
looks like a typo and this patch fixes that.

Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>