daemon/initlayer: Init(): remove unused stub for Windows

This package is only used in unix/linux files, so we don't
need a stub for Windows.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/initlayer/setup_windows.go

@@ -1,16 +0,0 @@
-package initlayer // import "github.com/docker/docker/daemon/initlayer"
-
-import (
-	"github.com/docker/docker/pkg/containerfs"
-	"github.com/docker/docker/pkg/idtools"
-)
-
-// Setup populates a directory with mountpoints suitable
-// for bind-mounting dockerinit into the container. The mountpoint is simply an
-// empty file at /.dockerinit
-//
-// This extra layer is used by all containers as the top-most ro layer. It protects
-// the container from unwanted side-effects on the rw layer.
-func Setup(initLayer containerfs.ContainerFS, rootIDs idtools.Identity) error {
-	return nil
-}