The system vulkan driver can get sulky if you don't free memory.

Bug: b/123749916
Change-Id: I9bf2de63a788200c401b41fa3efdfb36f3c15245
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27772
Presubmit-Ready: Ben Clayton <headlessclayton@gmail.com>
Tested-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>