Merge pull request #1564 from bangnoise/pr/IOSurface-CF-leaks

Fix leak of CoreFoundation objects during calls to vkUseIOSurfaceMVK()
diff --git a/MoltenVK/MoltenVK/Vulkan/vk_mvk_moltenvk.mm b/MoltenVK/MoltenVK/Vulkan/vk_mvk_moltenvk.mm
index 39b3994..72a8ac6 100644
--- a/MoltenVK/MoltenVK/Vulkan/vk_mvk_moltenvk.mm
+++ b/MoltenVK/MoltenVK/Vulkan/vk_mvk_moltenvk.mm
@@ -141,7 +141,7 @@
     VkQueue                                     queue,
     id<MTLCommandQueue>*                        pMTLCommandQueue) {
 
-    MVKQueue* mvkQueue = (MVKQueue*)queue;
+    MVKQueue* mvkQueue = MVKQueue::getMVKQueue(queue);
     *pMTLCommandQueue = mvkQueue->getMTLCommandQueue();
 }