rds_free_buf
rds_free_buf(&rds_dpool, bp, nbuf);
rds_free_buf(&rds_cpool, bp, nbuf);
rds_free_buf(pool, ep->ep_rcvpool.pool_headp,
void rds_free_buf(rds_bufpool_t *pool, rds_buf_t *bp, uint_t nbuf);