Fix crash on close content after cached GPU pointer cleanup.

libretro/LibretroGraphicsContext.cpp

@@ -73,10 +73,6 @@ void LibretroHWRenderContext::ContextDestroy() {
 #endif
 	}
 
-	LostBackbuffer();
-
-	gpu->DeviceLost();
-
 	if (!hw_render_.cache_context && !Libretro::useEmuThread) {
 		Shutdown();
 	}

libretro/LibretroVulkanContext.cpp

@@ -128,9 +128,6 @@ void LibretroVulkanContext::ContextReset() {
 
 void LibretroVulkanContext::ContextDestroy() {
    INFO_LOG(G3D, "LibretroVulkanContext::ContextDestroy()");
-
-   LostBackbuffer();
-   gpu->DeviceLost();
 }
 
 void LibretroVulkanContext::CreateDrawContext() {