There was linux specific code in Vulkan's BUILD.gn file.

Change-Id: I22b8cd0b97bd6acfb545e582c6e1dc784f00b2cb
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/32388
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>