drm_hwcomposer: Do not close duplicate gem handles in nvimporter

When closing gem handles in ReleaseBufferImpl, do not try to close
the same one more than once.

BUG=chrome-os-partner:46443
TEST=Play youtube video, minimize.  Observe no "Failed to close
gem handle" messages in logcat.

Change-Id: I06598f304e3bd167a77f105eb2be86595ada8f4d
Signed-off-by: Isaac Simha <isimha@nvidia.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
1 file changed