Fix unreachable return statements.

[damaki]

This fixes #81 where some return statements that were generated unconditionally, leading to unreachable return statements.

[AppVeyorBot]

:white_check_mark: Build fff 100-appveyor completed (commit https://github.com/meekrosoft/fff/commit/59a631f658 by @damaki)

[tiringjoel]

When will this pull request be completed? Our cppCheck currently fails because of the unreachable return statements. Would highly appreciate it.

[henrik-nil-acc]

@meekrosoft , please merge this, thanks

[shlomnissan]

@meekrosoft Any particular reason this wasn't merged in?

[wulfgarpro]

LGTM