Fix two uninitialized variables in the v4l2 access module

Fix two uninitialized variables in the v4l2 access module

Without this patch, the initial value on my system is for example 3, so that two much items are counted. In the second step the function breaks with a error code, when the information downloading of the non-existing item fails.

Signed-off-by: Alina Friedrichsen <x-alina@gmx.net>
Signed-off-by: Antoine Cellerier <dionoea@videolan.org>