Where a plaintiff mistakenly sued divisions of one corporation separately, and the jury awarded damages only as to infringing conduct by one division, the U.S. District Court did not err in denying a motion to amend the judgment.The 7th U.S. Circuit Court of Appeals affirmed a decision by U.S. District Judge Robert L. Miller Jr., Northern District of Indiana.Guitar Center makes and sells musical instruments. In 2010, it …