minigbm: fix uninitialized variable error

To fix the maybe uninitialized error we assign plane_type a starting
value.
The number zero corresponds to DRM_PLANE_TYPE_OVERLAY, so instead we
initialize plane_type to UINT64_MAX.

Bug: chromium:968030
Change-Id: I4fe119c1491926227151742041a73207971f56f0
Reviewed-on: https://chromium-review.googlesource.com/1634771
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: St├ęphane Marchesin <marcheu@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
1 file changed