All he has to do is deny symptoms.
"Did you get dizzy. nauseous, have vision problems, or headaches?"
"Nope" rinse and repeat.
There was a quote from Peyton Manning that he used to purposefully answer questions wrong in his baseline assessment so it'd be easier for him to return to playing if he got a concussion.
Regardless, Mahomes is back to practicing without symptoms, so it's pretty much assured that he's going to get the go-ahead to play on Sunday:
Patrick Mahomes remains in concussion protocol, 'took all the snaps' in light Chiefs practice (nfl.com)
Even before that, Andy Reid was saying Mahomes was perfectly ok shortly after the game. Mahomes is 100% playing