message: Remove an unnecessary argument
  Summary: Spotted by nightly clippy.
diff: @@ -140,11 +140,7 @@ fn render_attr(x: StarAttr) -> TokenStream {
  }
  /// Get the lifetimes that are mentioned in a given type and its nested generics.
  -fn get_lifetimes_inner<'a>(
  - ret: &mut HashSet<&'a syn::Lifetime>,
  - span: proc_macro2::Span,
  - typ: &'a syn::Type,
  -) {
  +fn get_lifetimes_inner<'a>(ret: &mut HashSet<&'a syn::Lifetime>, typ: &'a syn::Type) {
  match typ {
  syn::Type::Path(path) => {
  if let Some(segment) = path.path.segments.last() {
  @@ -156,35 +152,35 @@ fn get_lifetimes_inner<'a>(
  syn::GenericArgument::Lifetime(l) => {
  ret.insert(l);
  }
  - syn::GenericArgument::Type(t) => get_lifetimes_inner(ret, span, t),
  + syn::GenericArgument::Type(t) => get_lifetimes_inner(ret, t),
  _ => {}
  };
  }
  }
  syn::PathArguments::Parenthesized(args) => {
  for t in &args.inputs {
  - get_lifetimes_inner(ret, span, t);
  + get_lifetimes_inner(ret, t);
  }
  match &args.output {
  syn::ReturnType::Default => {}
  - syn::ReturnType::Type(_, t) => get_lifetimes_inner(ret, span, t),
  + syn::ReturnType::Type(_, t) => get_lifetimes_inner(ret, t),
  };
  }
  };
  }
  }
  - syn::Type::Group(g) => get_lifetimes_inner(ret, span, &g.elem),
  - syn::Type::Paren(p) => get_lifetimes_inner(ret, span, &p.elem),
  - syn::Type::Ptr(p) => get_lifetimes_inner(ret, span, &p.elem),
  + syn::Type::Group(g) => get_lifetimes_inner(ret, &g.elem),
  + syn::Type::Paren(p) => get_lifetimes_inner(ret, &p.elem),
  + syn::Type::Ptr(p) => get_lifetimes_inner(ret, &p.elem),
  syn::Type::Reference(r) => {
  if let Some(l) = &r.lifetime {
  ret.insert(l);
  };
  - get_lifetimes_inner(ret, span, &r.elem);
  + get_lifetimes_inner(ret, &r.elem);
  }
  syn::Type::Tuple(t) => {
  for t in &t.elems {
  - get_lifetimes_inner(ret, span, t);
  + get_lifetimes_inner(ret, t);
  }
  }
  _ => {}
  @@ -196,7 +192,7 @@ fn get_lifetimes_inner<'a>(
  /// e.g. `i32` would return ``, `Vec<(&'a str, &'b str)>` would return `<'a, 'b>`
  fn get_lifetimes(span: proc_macro2::Span, typ: &syn::Type) -> TokenStream {
  let mut ret = HashSet::new();
  - get_lifetimes_inner(&mut ret, span, typ);
  + get_lifetimes_inner(&mut ret, typ);
  if ret.is_empty() {
  TokenStream::new()
  } else {
  