If you have multiple 1098 mortgage forms, you’ll enter them one at a time. After going through the steps with the first one, you can add a lender when you get to the Mortgage deduction summary screen. (In the case of a refinance, it's best to enter the 1098 from your original loan before the 1098 from your refinance.)
But, if they're both from the same lender, and one of them has the “Corrected” checkbox marked at the top, enter the corrected 1098 and discard or shred the other one.