msm: camera: Fix for OOB security CR

If user passes an aribitary command with _IOC_DIR(cmd) == _IOC_NONE,
"arg" should not point to any arbitrary address.
Check for invalid command and return error

Change-Id: Ieae6c79a836d0ae71055725d7994a01bf17b9e05
Signed-off-by: Abhishek Abbanaveni <aabban@codeaurora.org>