Ruby

lib/test/unit.rb: use local output

• lib/test/unit.rb (Test::Unit::Runner#output): prefer local output to
  get rid of unexpected side effect in test/minitest/metametameta.rb.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35580 b2dd03c8-39d4-4d8f-98ff-823fe69b080e