make sure d3ddev is not null

inc/render_d3d9.h

@@ -0,0 +1,11 @@
+#pragma once
+
+typedef struct CUSTOMVERTEX { float x, y, z, rhw, u, v; } CUSTOMVERTEX;
+
+DWORD WINAPI render_d3d9_main(void);
+BOOL Direct3D9_Create();
+BOOL Direct3D9_Reset();
+BOOL Direct3D9_Release();
+BOOL Direct3D9_DeviceLost();
+
+extern HMODULE Direct3D9_hModule;