qdutils: Fix mapping in qdMetaData

With gralloc1, munmap is called at the last release() of the
buffer in the client process. Do not munmap in every metadata
call. Also moves the handle validation/mapping to a common
function.

CRs-Fixed: 2025982
Change-Id: I8f171d87e31368f4a9f19c916eceb1abda449000
1 file changed