node.c (node_buffer_elem_t): Use FLEX_ARY_LEN
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61805 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
node.c (node_buffer_elem_t): Use FLEX_ARY_LEN
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61805 b2dd03c8-39d4-4d8f-98ff-823fe69b080e