Simply comment the compute part and replace with a SELECT statement

-- COMPUTE SUM([Total(MB)]), SUM([Unused(MB)]), SUM([Used(MB)]), SUM([Index(MB)]), SUM([Data(MB)])

SELECT SUM([Total(MB)]), SUM([Unused(MB)]), SUM([Used(MB)]), SUM([Index(MB)]), SUM([Data(MB)]) FROM dbo.##FO

Would work for all SQL Server versions.