The 5498-SA is the form that reports contributions to your HSA. These contributions can be from your employer, from you as payroll deductions, or from you in direct contributions by[assing your employer.
You are required to file for 8889 if you made any contributions from or distributions to your HSA. The 8889 is the form that determines your annual HSA contribution limit and also reports on contributions and distributions.
Therefore, I am not sure that entering information from the 5498-SA is a mistake. If you or your employer made contributions to the HSA, then you must report the HSA and have TurboTax create the 8889.
If you just want to delete what you have entered and start over, then do the following:
Delete the 8889 form and related forms. Do this by going to
My Account (at the top), click on
Tools, then on
Delete a Form.
Delete any "Form 1099-SA" you see, as well as any "Form 8889-T" and "Form 8889-S".