tri/cube: Adjust demo_resize() to API changes.
diff --git a/demos/cube.c b/demos/cube.c
index b1c4c6f..d2c20d0 100644
--- a/demos/cube.c
+++ b/demos/cube.c
@@ -1892,10 +1892,12 @@
 
     for (i = 0; i < demo->swapchainImageCount; i++) {
         vkDestroyImageView(demo->device, demo->buffers[i].view);
-        vkDestroyCommandBuffer(demo->device, demo->buffers[i].cmd);
+        vkFreeCommandBuffers(demo->device, demo->cmd_pool, 1, &demo->buffers[i].cmd);
     }
     free(demo->buffers);
 
+    vkDestroyCommandPool(demo->device, demo->cmd_pool);
+
 
     // Second, re-perform the demo_prepare() function, which will re-create the
     // swapchain: