message: tracing: rename new dispatcher -> dispatch
  It happened again:
diff: @@ -2349,7 +2349,7 @@ macro_rules! if_log_enabled {
  };
  ($lvl:expr, $if_log:block else $else_block:block) => {
  if $crate::level_to_log!($lvl) <= $crate::log::STATIC_MAX_LEVEL {
  - if !$crate::dispatcher::has_been_set() {
  + if !$crate::dispatch::has_been_set() {
  $if_log
  } else {
  $else_block
  