yaml/api.c: fix typo

* ext/psych/yaml/api.c (yaml_emitter_delete): fix typo 'empty'
  with 'emitter'.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44918 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/psych/yaml/api.c

@@ -395,7 +395,7 @@ yaml_emitter_delete(yaml_emitter_t *emitter)
     }
     QUEUE_DEL(emitter, emitter->events);
     STACK_DEL(emitter, emitter->indents);
-    while (!STACK_EMPTY(empty, emitter->tag_directives)) {
+    while (!STACK_EMPTY(emitter, emitter->tag_directives)) {
         yaml_tag_directive_t tag_directive = POP(emitter, emitter->tag_directives);
         yaml_free(tag_directive.handle);
         yaml_free(tag_directive.prefix);