I press select and back and it gets rid of it for me (by sending it to the chat window and backing out) but its honestly rather annoying as I don't use the pointer icon to target something and I don't like just having a pointer in the center of my screen. For a summoner, it's like watching a movie on your computer and having a mouse pointer pop up in the center every 30 seconds. You can leave it there and just have it bug you the entire time or have to move the mouse pointer every time.