message: snapshotter: remove daemon field from snapshotter
  daemon.Daemon is not used in struct snapshotter, so remove it.
diff: @@ -25,7 +25,6 @@ import (
  "github.com/pkg/errors"
  "github.com/dragonflyoss/image-service/contrib/nydus-snapshotter/config"
  - "github.com/dragonflyoss/image-service/contrib/nydus-snapshotter/pkg/daemon"
  fspkg "github.com/dragonflyoss/image-service/contrib/nydus-snapshotter/pkg/filesystem/fs"
  "github.com/dragonflyoss/image-service/contrib/nydus-snapshotter/pkg/filesystem/nydus"
  "github.com/dragonflyoss/image-service/contrib/nydus-snapshotter/pkg/filesystem/stargz"
  @@ -46,7 +45,6 @@ type snapshotter struct {
  fs fspkg.FileSystem
  stargzFs fspkg.FileSystem
  manager *process.Manager
  - daemon *daemon.Daemon
  }
  func (o *snapshotter) Cleanup(ctx context.Context) error {
  