refactored to not use return statements so Rails 4.1 still works

[ngottlieb]

See here: http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html#usage-of-return-within-inline-callback-blocks

So using it in Rails 4.1 errors in lib/cancan_strong_parameters/controller.rb on line 88.

I pulled all the return statements with some very minor refactoring.