Use predicate method and eliminate local

Library/Contributions/cmd/brew-test-bot.rb

@@ -116,13 +116,12 @@ class Step
 
     @time = Time.now - start_time
 
-    success = $?.success?
-    @status = success ? :passed : :failed
+    @status = $?.success? ? :passed : :failed
     puts_result
 
     if File.exist?(log)
       @output = File.read(log)
-      if has_output? and (not success or @puts_output_on_success)
+      if has_output? and (failed? or @puts_output_on_success)
         puts @output
       end
       FileUtils.rm(log) unless ARGV.include? "--keep-logs"