msm: camera: icp: Keep the mutex locked when cleaning up

If any of the steps in the ICP open fails, release the mutex after
the cleanup is done, to protect against concurrency issues.

Change-Id: Ie9a817d58677dd7df33158622f54e5774b6279f9
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>