formula_auditor: fix versioned alias audit
formula_auditor: fix versioned alias audit

* Fix audit not being run at all due to always-false condition.
* Don't fail audit if versioned alias would clash with a versioned formula.
* Allow versioned aliases with the name of another alias.

nandub/brew,Homebrew/brew,MikeMcQuaid/brew,nandub/brew,nandub/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,JCount/brew,MikeMcQuaid/brew,Homebrew/brew,JCount/brew,Homebrew/brew,nandub/brew,JCount/brew,JCount/brew,Homebrew/brew