message: better assignment to option
diff: @@ -115,14 +115,12 @@ impl rlp::Decodable for Node {
  }
  }
  }
  - let mut value: Option<Vec<u8>> = None;
  - if !rlp.at(Node::RADIX)?.is_empty() {
  - value = Some(rlp.at(Node::RADIX)?.as_val()?)
  - }
  - Ok(Node::Full(FullNode {
  - nodes: nodes,
  - value: value,
  - }))
  + let value: Option<Vec<u8>> = if !rlp.at(Node::RADIX)?.is_empty() {
  + Some(rlp.at(Node::RADIX)?.as_val()?)
  + } else {
  + None
  + };
  + Ok(Node::Full(FullNode {nodes, value }))
  }
  RlpPrototype::Data(Node::HASH_SIZE) => {
  Ok(Node::Hash(rlp.as_val()?))
  