[graphite] Fix commandqueue memory leak

Bug: skia:12466
Change-Id: Icbd4fd6098c8a50164613e630db476bf8ea41517
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/459177
Auto-Submit: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
1 file changed