message: style: use Once::new
diff: use std::mem;
  use std::ptr;
  -use std::sync::{Once, ONCE_INIT};
  +use std::sync::Once;
  use libc::{c_char, c_int, c_long, c_void};
  // Used to initialize the TCL interpreter exactly once.
  -static ONCE: Once = ONCE_INIT;
  +static ONCE: Once = Once::new();
  /// Text is a TCL string object backed by a Rust string.
  ///
  