[vk] Handling threading missuse of VkQueue

src/video_core/renderer_vulkan/renderer_vulkan.cpp

@@ -177,6 +177,8 @@ try
 
 RendererVulkan::~RendererVulkan() {
     scheduler.RegisterOnSubmit([] {});
+    // Acquire submit_mutex before WaitIdle to prevent simultaneous queue access
+    std::scoped_lock lock{scheduler.submit_mutex};
     void(device.GetLogical().WaitIdle());
 }
 

src/video_core/renderer_vulkan/vk_blit_screen.cpp

@@ -30,7 +30,8 @@ BlitScreen::~BlitScreen() = default;
 void BlitScreen::WaitIdle() {
     present_manager.WaitPresent();
     scheduler.Finish();
-    device.GetLogical().WaitIdle();
+    // Note: scheduler.Finish() already waits for GPU and synchronizes submit_mutex
+    // Calling device.WaitIdle() here causes threading errors (simultaneous queue access)
 }
 
 void BlitScreen::SetWindowAdaptPass() {