This was entirely reportable on your 2017 tax return. Done properly on your 2017 tax return there would have been no excess carried to a 2018, so no 2018 Form 5329. The only amount that would have appeared on your 2017 Form 5329 is the amount shown in box 2a of the Form 1099-R if there was a code 1 in box 7 in addition to the code P.
