Update containerd to 66b984ee33

Signed-off-by: Lantao Liu <lantaol@google.com>

vendor/github.com/Microsoft/hcsshim/internal/wclayer/unpreparelayer.go

@@ -0,0 +1,23 @@
+package wclayer
+
+import (
+	"github.com/Microsoft/hcsshim/internal/hcserror"
+	"github.com/sirupsen/logrus"
+)
+
+// UnprepareLayer disables the filesystem filter for the read-write layer with
+// the given id.
+func UnprepareLayer(path string) error {
+	title := "hcsshim::UnprepareLayer "
+	logrus.Debugf(title+"path %s", path)
+
+	err := unprepareLayer(&stdDriverInfo, path)
+	if err != nil {
+		err = hcserror.Errorf(err, title, "path=%s", path)
+		logrus.Error(err)
+		return err
+	}
+
+	logrus.Debugf(title+"succeeded path=%s", path)
+	return nil
+}