Backends: Vulkan: Suppress trivially-copyable warning (#8537)

backends/imgui_impl_vulkan.cpp

@@ -251,7 +251,7 @@ struct ImGui_ImplVulkan_ViewportData
     bool                                    SwapChainNeedRebuild;   // Flag when viewport swapchain resized in the middle of processing a frame
     bool                                    SwapChainSuboptimal;    // Flag when VK_SUBOPTIMAL_KHR was returned.
 
-    ImGui_ImplVulkan_ViewportData() { WindowOwned = SwapChainNeedRebuild = SwapChainSuboptimal = false; memset(&RenderBuffers, 0, sizeof(RenderBuffers)); }
+    ImGui_ImplVulkan_ViewportData() { WindowOwned = SwapChainNeedRebuild = SwapChainSuboptimal = false; memset((void*)&RenderBuffers, 0, sizeof(RenderBuffers)); }
     ~ImGui_ImplVulkan_ViewportData() { }
 };