test_rubyoptions.rb: clean crash log

* test/ruby/test_rubyoptions.rb (test_segv_loaded_features): clean
  crash log on OS X after intentional segv.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48860 b2dd03c8-39d4-4d8f-98ff-823fe69b080e