Vendor in latest containers/buildah

Switch from projectatomic/buildah to containers/buildah

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/containers/buildah/chroot/selinux.go

@@ -0,0 +1,22 @@
+// +build linux,selinux
+
+package chroot
+
+import (
+	"github.com/opencontainers/runtime-spec/specs-go"
+	selinux "github.com/opencontainers/selinux/go-selinux"
+	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+// setSelinuxLabel sets the process label for child processes that we'll start.
+func setSelinuxLabel(spec *specs.Spec) error {
+	logrus.Debugf("setting selinux label")
+	if spec.Process.SelinuxLabel != "" && selinux.EnforceMode() != selinux.Disabled {
+		if err := label.SetProcessLabel(spec.Process.SelinuxLabel); err != nil {
+			return errors.Wrapf(err, "error setting process label to %q", spec.Process.SelinuxLabel)
+		}
+	}
+	return nil
+}