After the PGA Tour Champions’ James Hardie Pro Football Hall of Fame Invitational, the first week of March, Scott McCarron had a scratchy throat. So he looked inside his mouth with a flashlight to see what it was.  The three-time PGA Tour winner found a little white spot about the size of an eraser and decided to call his doctor.  He went in the next day to get it checked out, and his doctor would send him to an ear, nose and throat specialist, where McCarron, 60, underwent a biopsy.  Still, McCarron didn’t think much of it, believing it might be a bacterial infection. He left to play the Cologuard Classic, where he finished T15. However, on the way to his next event, he received a harrowing call.  “[The doctor] called me and said, ‘You have cancer,’” McCarron told the PGA Tour Champions this week. “So, at that point, he didn’t know exactly what kind.…