Code review comment for lp:~soren/nova/avoid-zombie-chains

Just some really really minor nits:

> 10 + if self.instances.pop(instance['id'], False):

Since instance['id'] isn't a bool, the fallback should probably be None.

> 15 - 'filtered'), instance['id'])
> 6 + 'filtered'), instance['id'])

Any reason to include this in the final patch?