Charcoal 14 07 anonymous controller acu158421

RSpec Rails allows [anonymous controllers](https://www.relishapp.com/rspec/rspec-rails/docs/controller-specs/anonymous-controller) to be defined, which set the `described_class` to an instance of `Class` rather than a nice class name. When we use this repo for CI output, we then get some specs under a group of &lt;#Class:0xF00>, which isn't very helpful.

I inverted the logic in getting the class name to use the top-level description first, then the class name. I'm not sure if a) this will break anyone's use-case (there didn't appear to be any specs indicating a preference either way) and b) `example.example_group.top_level_description` will ever be falsy. If not, then the `||` is probably redundant.

(The relevant line was initially introduced by https://github.com/rightscale/right_develop/commit/a61b3002eef6989c7b1c5bc39e4fa35d7e906e23#diff-5f00fcef9c7d276a85cd63ccaba4b1ffL51, if that helps.)