PHOTO (Duke Athletics): Gunnar Holmberg scans the field for an open receiver against A&T. Visit my website homepage, TomShanahan.Report By TOM SHANAHAN ACC Network analyst Eric Mac Lain offered more than a routine break down of the conference’s top five quarterbacks through the first two weeks of the season. He was invited on Tuesday morning's Packer and Durham Show to list them in order. Returning starters, naturally, topped his list. He named Virginia’s Brennan Armstrong, North Carolina’s Sam…