clang-modernize -use-nullptr

and s/\bNULL\b/nullptr/g for *.cpp/h/mm files not compiled on my machine

Source/Core/InputCommon/ControllerInterface/ExpressionParser.h

@@ -47,7 +47,7 @@ class ExpressionNode;
 class Expression
 {
 public:
-	Expression() : node(NULL) {}
+	Expression() : node(nullptr) {}
 	Expression(ExpressionNode *node);
 	~Expression();
 	ControlState GetValue();