This is just a small hack to prevent screen tearing.
Later, we should properly implement VkSemaphore to
prevent this.

Bug: b/132458423
Change-Id: I825f100a73c4b5b9b909eba83552cbec51ff1792
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/31152Reviewed-by: Alexis Hétu <sugoi@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Hernan Liatis <hliatis@google.com>