setup.mak: discard BASERUBY output
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62110 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
setup.mak: discard BASERUBY output
it contains multiple commands.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62110 b2dd03c8-39d4-4d8f-98ff-823fe69b080e