this would be an interesting battle, I can see Ego violently ejecting Hulk out of his body and into the next galaxy. I don't think Ego could kill him.
Ego's had a tough time fighting Surfer. Hulk's gonna do so much more damage than Surfer was ever willing to.
at best Ego wins via bfr. at worst, the planet explodes and we find out if Ego has a form beyond the stupid asteroid body.