msm: camera: Fix various small issues in Actuator driver

Bound check and validate userspace parameters direction,
number of steps and direction sign. Also fix possible
memory leak in certain error cases.

CRs-Fixed: 511349
Change-Id: Icaa324468574494fb40f2de78e522090806744cb
Signed-off-by: Hariram Purushothaman <hpurus@codeaurora.org>
Signed-off-by: Gopal G Goberu <ggober@codeaurora.org>