It is wrong to expect the last output is "exit".

When lb.join is commented out as [ruby-dev:30653] says,
@keeper is living until the program truely die.
So after it outputs "exit.", it may output "#{i}: cont".

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35289 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_thread.rb

@@ -218,7 +218,6 @@ class TestThread < Test::Unit::TestCase
     3.times {
       result = `#{EnvUtil.rubybin} #{lbtest}`
       assert(!$?.coredump?, '[ruby-dev:30653]')
-      assert_equal("exit.", result[/.*\Z/], '[ruby-dev:30653]')
     }
   end