Vulkan: Move pruneOrphanedBufferBlocks to last RendererVk::cleanupGarbage() should call pruneOrphanedBufferBlocks() after clean up mSuballocationGarbage, so that we will be able to find the orphaned buffer block being empty if mSuballocationGarbage actually made it empty. Bug: chromium:1318110 Change-Id: I0cc6e45c192f406e7bbb15c7427d30e06208dd06 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3611648 Reviewed-by: Ian Elliott <ianelliott@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Charlie Lao <cclao@google.com>