Fix test refactoring.
Fix test refactoring.

finally does not receive the value.

jasonmit/broccoli-caching-writer,chadhietala/broccoli-caching-writer,twokul/broccoli-caching-writer,joliss/broccoli-caching-writer,stefanpenner/broccoli-caching-writer,ember-cli/broccoli-caching-writer