minigbm: remove `close_gem_handle`

There are two gem close handles. Remove one of them and use `drv_gem_close` instead.

Bug=b:266776512
TEST=cts

Change-Id: I4dd1ab884626623e7d5f2024296c241cf75a9402
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/4461311
Reviewed-by: Yiwei Zhang <[email protected]>
Tested-by: Dawn Han <[email protected]>
Commit-Queue: Dawn Han <[email protected]>
3 files changed