setup.mak: follow up r53303
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53310 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
setup.mak: follow up r53303
now.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53310 b2dd03c8-39d4-4d8f-98ff-823fe69b080e