msm: camera: sync: Remove unnecessary alloc-free

There are unnecessary calls to kzalloc and kfree in
cam_sync_deinit_object() that can affect performance.
Removing these calls to optimize.

Change-Id: Icd090fc3c4846a6f5c169e0001e829f30f5381a0
Signed-off-by: Harsh Shah <harshs@codeaurora.org>