Ruby

vm_method.c: fix assertion

• vm_method.c (prepare_callable_method_entry): assert same
  condition only once for each case, not twice for module instance
  method.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53977 b2dd03c8-39d4-4d8f-98ff-823fe69b080e