(#6820) Fix invalid next that should be a return

The old code under ruby 1.8.7 if it was hit would result in:

unexpected next (LocalJumpError)

In Ruby 1.9 it doesn't even give you the chance to run the code since
you get:

compile error (SyntaxError)

The code isn't tested so the intented behavior isn't clear, but in
context this looks like the right change.

Reviewed-by: Jacob Helwig <jacob@puppetlabs.com>