fileutils.rb: fix traversal loop
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41283 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
fileutils.rb: fix traversal loop
remove same directory only.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41283 b2dd03c8-39d4-4d8f-98ff-823fe69b080e