msm: camera: Fixed memory leak and added NULL check

1. Dynamic memory stored in cofig_cam allocated through
function kzalloc can be lost in the error cases. Hence
common error handling along with de-allocation is added.
2. Pointer ctrl checked for NULL and returned on NULL.

Change-Id: I53ca31159507a3bc059507cdfda897028a241065
Signed-off-by: Jeyaprakash Soundrapandian <jsound@codeaurora.org>