Revert "gralloc: Return an error if the buffer was not mapped"

This reverts commit 7a86b840ae427137955726ec8ef8825e29edb141.

CTS failures were seen in camera in cases where EIS uses the
gralloc private handle.

Change-Id: Ibe9d6331175ab389d724fb10a1d73421456dcd47
CRs-Fixed: 1048932
1 file changed