LIST_FIRST
if (LIST_FIRST(&ahd->pending_scbs) != NULL) {
first_scb = LIST_FIRST(free_list);
first_scb = LIST_FIRST(free_list);
if ((scb = LIST_FIRST(&ahd->scb_data.any_dev_free_scb_list)) == NULL) {
if (LIST_FIRST(&ahd->pending_scbs) != NULL) {
scbp_next = LIST_FIRST(&ahd->pending_scbs);
if (LIST_FIRST(&ahc->pending_scbs) != NULL) {
scbp_next = LIST_FIRST(&ahc->pending_scbs);
if (LIST_FIRST(&ahc->pending_scbs) != NULL) {
for ((var) = LIST_FIRST((head)); \
LIST_FIRST((head)) = NULL; \
if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
LIST_FIRST((head)) = (elm); \
(elm)->field.le_prev = &LIST_FIRST((head)); \
task = LIST_FIRST(&vruntime_head);