msm: camera: ispif: Fix for few code warnings

Due to uninitialized variables being used warnings
are reported.Made changes to initialize variables
before usage.

CRs-Fixed: 994269

Change-Id: Id0336e17e2d067d9d27dda3b4b19b6d1f48565e4
Signed-off-by: Meera Gande <mgande@codeaurora.org>