It wasn’t easy on Saturday afternoon in Columbus, but Ohio State got the job done and picked up a 21-17 win over Nebraska to improve to 6-1 on the season. The Buckeyes had some important visitors on campus, headlined by Reserve (La.) Edna Karr five-star defensive lineman Jahkeem Stewart. The 6-foot-5.5, 270-pounder has the Big Ten powerhouse in his top four schools and got another look at what Ryan Day, Larry Johnson and Co. have to offer. Saturday was the second time that Stewart saw the Buckeyes in action this season, as he was also in Eugene when they fell to Oregon — another one of his top…