message: doc: resync TBM should_use comment
  The TBM `should_use` comment drifted slightly
  out of sync with the code when a better usage huristic
  was added. I've shaved the yak.
diff: @@ -680,9 +680,7 @@ impl BoyerMooreSearch {
  /// A third case is if the pattern is sufficiently long. The idea
  /// here is that once the pattern gets long enough the Tuned
  /// Boyer-Moore skip loop will start making strides long enough
  - /// to beat the asm deep magic that is memchr. Unfortunately,
  - /// I had trouble proving a useful turnover point. Hopefully,
  - /// we can find one in the future.
  + /// to beat the asm deep magic that is memchr.
  fn should_use(pattern: &[u8]) -> bool {
  // The minimum pattern length required to use TBM.
  const MIN_LEN: usize = 9;
  