Fix cleanup of swapchain images in the shared case am: 31b85c23

    //

    // TODO(jessehall): The error path here is the same as DestroySwapchain,

    // but not the non-error path. Should refactor/unify.

    if (!swapchain->shared) {

    for (uint32_t i = 0; i < num_images; i++) {

        Swapchain::Image& img = swapchain->images[i];

        if (img.dequeued) {

            if (!swapchain->shared) {

                surface.window->cancelBuffer(surface.window.get(), img.buffer.get(),

                                             img.dequeue_fence);

                img.dequeue_fence = -1;

                img.dequeued = false;

            }

        }

        if (result != VK_SUCCESS) {

            if (img.image)

                dispatch.DestroyImage(device, img.image, nullptr);

        }

    }

    }

    if (result != VK_SUCCESS) {

        swapchain->~Swapchain();