Update the snapshotter docs to refer to the snapshots package for
WithLabels.
@@ -163,7 +163,7 @@ func (u *Usage) Add(other Usage) {
// key and descending from the empty parent "". To prevent our layer from being
// garbage collected during unpacking, we add the `containerd.io/gc.root` label:
//
-// noGcOpt := snapshotter.WithLabels(map[string]string{
+// noGcOpt := snapshots.WithLabels(map[string]string{
// "containerd.io/gc.root": time.Now().UTC().Format(time.RFC3339),
// })
// mounts, err := snapshotter.Prepare(ctx, key, "", noGcOpt)
