message: clippy: fix toplevel_ref_arg warnings
diff: @@ -101,7 +101,7 @@ fn perform_merge(segment_ids: &[SegmentId],
  // first we need to apply deletes to our segment.
  info!("Start merge: {:?}", segment_ids);
  - let ref index = segment_updater.0.index;
  + let index = &segment_updater.0.index;
  let schema = index.schema();
  let mut segment_entries = vec![];
  