vidc: Error handling for memory heap mapping.

Memory heap should be unsecured if secure call is successful.
This change will make sure that an unsecure will be called
only if securing of the memory heap went through fine.

CRs-Fixed: 393041
Change-Id: I49dd81d1846fc6936518c750a32921c8498ddb95
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>
Signed-off-by: Riaz Ur Rahaman <riazr@codeaurora.org>