CCodec: Avoid OOB memory access in some cases

During releaseBuffer, if the caller has not provided
pointer to c2buffer, then no need to generate compBuffer,
if doesn't exist already.

If the raw color format is not recognized by frameworks,
then ImageCopy (inside asC2Buffer function) might end up
resulting in out-of-bound memory access for few resolutions

CRs-Fixed: 3341384
Change-Id: I39b06a571e6244931c73ef99675f4d9e2dcf247e