Vulkan: Remove transient cmd buffer workaround We no longer need this workaround. Also mCommandPoolFreeList dead code. Bug: angleproject:3508 Change-Id: Ib73ddd431eb1bf9a55c3421111af4df5976cc1fb Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2033485 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tobin Ehlis <tobine@google.com> Commit-Queue: Tobin Ehlis <tobine@google.com>