msm-camera: Addressing possible overflow conditions

Changes to address possible integer overflow and incorrect
array indexing conditions.

Change-Id: I5b1f53fa8e4cd9ba24f24929f1c5bb43b1ae06f5
CRs-Fixed: 897259
Signed-off-by: Trilokesh Rangam <tranga@codeaurora.org>
Signed-off-by: Yang Guang <guyang@codeaurora.org>
Signed-off-by: VijayaKumar T M <vtmuni@codeaurora.org>