msm: vidc: Fix operating issues

Operating is caulculated incorrectly due to the wrong usage
of instance pointers. This change fixes the same.

CRs-Fixed: 2048733
Change-Id: I737471ceb48fdcb2ef3e54849ef5cd929df9d579
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>