Fix a memory leak in ExpressionParser.cpp

Because there's a return here, expr should be deleted since it's not assigned to anything before returning.

Source/Core/InputCommon/Src/ControllerInterface/ExpressionParser.cpp

@@ -549,7 +549,10 @@ ExpressionParseStatus ParseExpressionInner(std::string str, ControlFinder &finde
 	Parser p(tokens, finder);
 	status = p.Parse(&expr);
 	if (status != EXPRESSION_PARSE_SUCCESS)
+	{
+		delete expr;
 		return status;
+	}
 
 	*expr_out = expr;
 	return EXPRESSION_PARSE_SUCCESS;