Where does it tell you that to enter something from your W-2? A screen in the HSA interview does refer to an entry on box 12 on your W-2, but once you entered your W-2, that was enough.
The code W in box 12 of the W-2 is the sum of the contributions that your employer made to your HSA plus what you contributed by means of payroll deduction.
Again, please do not enter this number anywhere else on the return.