tap: tweak Ruby style for readability.

Author: MikeMcQuaid

Library/Homebrew/tap.rb

@@ -1116,7 +1116,7 @@ def audit_exception(list, formula_or_cask, value = nil)
       return false unless list.include? formula_or_cask
       return list[formula_or_cask] if value.blank?
 
-      return list[formula_or_cask].include? value if list[formula_or_cask].is_a? Array
+      return list[formula_or_cask].include?(value) if list[formula_or_cask].is_a?(Array)
 
       list[formula_or_cask] == value
     end