If you are trying for this and know you will lose your current hand, you can hit the PS3 button on your controller and exit back to the dashboard then reload the game and start again. You can go all-in over and over then exit as needed to keep from losing any chips towards this.
If you are not familiar with the rules of poker, look at the list of names on the top of the screen instead. It will show 100% for the winner of the hand after the 5th card is dealt on the table. If the 100% is showing on anyone else instead of your name, hit the PS3 button and exit to dashboard to try again.