timer_nextisdue
if (timer_nextisdue(&MRT2MC(m)->timer, now) !=
if (timer_nextisdue(&expire_timer, getmonotime()) != NULL) {
if ((t = timer_nextisdue(&rs->timers, now)) != NULL) {
if ((pt = timer_nextisdue(&p->timers, now)) != NULL) {
struct timer *timer_nextisdue(struct timer_head *, monotime_t);