test_system.rb: fix test
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38956 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_system.rb: fix test
meaningless test. [Bug #7482]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38956 b2dd03c8-39d4-4d8f-98ff-823fe69b080e