message: Use inspect rather than map
  `map(|x| { do_something(&x); x })` can be replaced with
  `inspect(|x| do_something(&x)`.  There is probably a lint for that, but
  we don't have all the lints on yet.
diff: @@ -324,10 +324,7 @@ impl LossRecovery {
  .is_none());
  self.spaces[PNSpace::ApplicationData]
  .remove_ignored()
  - .map(|p| {
  - self.cc.discard(&p);
  - p
  - })
  + .inspect(|p| self.cc.discard(&p))
  .collect()
  }
  @@ -424,10 +421,7 @@ impl LossRecovery {
  self.spaces
  .iter_mut()
  .flat_map(|spc| spc.remove_ignored())
  - .map(|p| {
  - cc.discard(&p);
  - p
  - })
  + .inspect(|p| cc.discard(&p))
  .collect()
  }
  