Even easier: Before starting any round, open the game client (click the "Play Now" button). Look at your equipment on the right side of the screen. The quantity of the ball you have equipped is displayed in the box with the golf ball.
If you know before you even tee off that you have enough in stock you can just ignore the notice. No one should ever have to click on that annoying thing.
It should be the responsibility of the player to check stock before starting a game.