Minor fix for compilation as C++20

Author: adam-sawicki-a

src/D3D12Sample.cpp

@@ -41,7 +41,7 @@ namespace PS
     #else
         extern "C" { __declspec(dllexport) extern const UINT D3D12SDKVersion = D3D12_SDK_VERSION; }
     #endif
-    extern "C" { __declspec(dllexport) extern const char* D3D12SDKPath = u8".\\D3D12\\"; }
+    extern "C" { __declspec(dllexport) extern const char* D3D12SDKPath = ".\\D3D12\\"; }
 #endif
 
 enum class ExitCode : int