message: simplify tree preparation
diff: @@ -9,18 +9,7 @@ fn prepare_tree(vec: Vec<NodeData>) -> Tree {
  // integer log2 of (vec.len()+1), -1
  let mut h = (32 - ((vec.len()+1) as u32).leading_zeros() - 1)-1;
  let mut peak_pos = (1 << (h+1)) - 1;
  -
  let mut nodes = Vec::new();
  - let mut root_peak: Entry = vec[peak_pos-1].clone().into();
  -
  - root_peak.update_siblings(
  - EntryLink::Stored((peak_pos - (1<<h) - 1) as u32),
  - EntryLink::Stored((peak_pos - 2) as u32),
  - );
  - nodes.push(((peak_pos-1) as u32, root_peak));
  -
  - // + 2^(h+1)-1
  - peak_pos = peak_pos + (1 << (h+1)) - 1;
  loop {
  