GitLab

Fix mailbox driver incompatible cast bug and control flow issue that
was flagged by Coverity Scan.
Signed-off-by: Abdul Halim, Muhammad Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: I3f34e98d24e40139d31cf7d5b9b973cd2d981065