rds_ib_ring_init
void rds_ib_ring_init(struct rds_ib_work_ring *ring, u32 nr);
rds_ib_ring_init(&ic->i_send_ring, ic->i_send_ring.w_nr);
rds_ib_ring_init(&ic->i_recv_ring, ic->i_recv_ring.w_nr);
rds_ib_ring_init(&ic->i_send_ring, 0);
rds_ib_ring_init(&ic->i_recv_ring, 0);