loop.handles_queue not clean in in uv_loop_close()

[seanshpark]

use 239ab0b79c44b983862f9eb55db3c9a5d30d480a
run tuvtester, timer test case will fail at TUV_ASSERT(0 == uv_loop_close(uv_default_loop()));

in uv_loop_close(),

  QUEUE_FOREACH(q, &loop->handles_queue) {
    h = QUEUE_DATA(q, uv_handle_t, handle_queue);
    if (!(h->flags & UV__HANDLE_INTERNAL)) {
      return UV_EBUSY;
    }
  }

will return UV_EBUSY as handles_queue is not empty, but should be emtpy

[seanshpark]

fixed with c173ecf