All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Repeating invoking Allaah's Blessings upon the Prophet, sallallaahu alyhi wa sallam (after the final Tashahhud) or the Du'a for seeking refuge from the punishment of the grave and the like does not require Sujood as-Sahw (prostrations of forgetfulness).
Hence, it is correct that you did not perform Sujood as-Sahw and you are not required to do anything else.
For more benefit, please refer to Fatwa 83932.
Allaah Knows best.