A federal judge threw out the claims of seven former student-athletes who allege they suffered brain and neurocognitive injuries because manufacturer Riddell Inc. did not adequately warn them of the risks of wearing its football helmets.In a written opinion Monday, U.S. District Judge Matthew F. Kennelly of the Northern District of Illinois held the plaintiffs do not have the evidence needed to prove their claims against Riddell and its parent company, BRG Sports Inc.The testimony of a witness designated by the plaintiffs …