A Chicago police officer didn’t need a warrant to stop and search a van he suspected was transporting drugs, a federal judge has ruled.In a written opinion Friday, U.S. District Judge Amy St. Eve rejected the argument that the search and seizure of the vehicle Francisco Mayorga was driving violated the Fourth Amendment.St. Eve held Mayorga’s failure to wear a seat belt gave officer Angelo Panagiotopoulos all the authority he needed to stop the van.And the odor of marijuana emanating from the van was enough to …