The only way I've found to get an amount to appear on line B of TurboTax's Form 502SU Income from U.S. Obligations Smart Worksheet is to enter it manually on this line. It does not propagate from anywhere else that I can find, nowhere from any entries made in the Federal Taxes section in TurboTax. It seems to be a value entered directly by the user on the Capital Gains From U.S. Obligations are Tax Free page in the Maryland State section. If the value there should be zero, you should be able to simply delete the value.
