I have attached a patch that tries to make some of the comments in `scheduler.c` easier to follow, such as the comments that reference the old `channels_waiting_for_cells` and `channels_waiting_to_write` lists that were removed in [commit 3530825c5](https://github.com/torproject/tor/commit/3530825c53b7a28cf894b64e6d97aa90d0acccae). It also simplifies a couple of the channel state changes.