Hole In One
It’s really unlikely that any person playing a game of golf – even the most experienced professional – will get a hole in one during a game.
It is still possible though. Players do get them from time to time, but it’s not why most people play.
Similarly, at your viva it’s possible you’ll get no corrections but it’s not very likely. It’s possible your viva will be finished in less than an hour but there’s not much that you can do to bring it about. And it’s possible that you’ll be asked a question that brings you to shocked silence, but far, far more likely that you’d have something to say.
You didn’t do all of that the work for a quick viva, an easy time and a hope that you wrote your thesis perfectly. You did the work and in the process learned how to do it well. You learned how to be a good, capable researcher.
Now the viva is your time to show your examiners you can do it. It’s not a rush, it’s not a game and it’s not done with a hope that it will be done as quickly as possible.