A staff shortage at Rikers Island left two jail units without correction officers for more than 24 hours on Tuesday and Wednesday, a prisoner reported — and a city oversight board said the ongoing personnel problems factored in a wave of suicides in the jails since December. Two Rikers units — known as 3 West and 3 North in the Otis Bantum Correctional Center — were without correction officers through at least through noon Wednesday, leaving inmates in the strange position of helping other inmates get to court transport and video conferences.