msm: camera: icp: KW work issue in ICP

During packet preprocessing, if packet has no command buffers
it will lead to dereferencing null address. Similarly, during
io patching, null or garbage address may be used.
This change initializes the address and applies null check
while accessing it.

Change-Id: I116928aeed05eb897a5a557d71724110628a9a70
Signed-off-by: Alok Pandey <akumarpa@codeaurora.org>