Minor code review feedback

Src/PlatformHelpers.h

@@ -73,5 +73,5 @@ namespace DirectX
 
     typedef std::unique_ptr<void, handle_closer> ScopedHandle;
 
-    inline HANDLE safe_handle(HANDLE h) { return (h == INVALID_HANDLE_VALUE) ? 0 : h; }
+    inline HANDLE safe_handle(HANDLE h) { return (h == INVALID_HANDLE_VALUE) ? nullptr : h; }
 }

XWBTool/xwbtool.cpp

@@ -99,7 +99,7 @@ namespace
 
     typedef std::unique_ptr<void, handle_closer> ScopedHandle;
 
-    inline HANDLE safe_handle(HANDLE h) { return (h == INVALID_HANDLE_VALUE) ? 0 : h; }
+    inline HANDLE safe_handle(HANDLE h) { return (h == INVALID_HANDLE_VALUE) ? nullptr : h; }
 
     struct find_closer { void operator()(HANDLE h) { assert(h != INVALID_HANDLE_VALUE); if (h) FindClose(h); } };