ALLOC_NEXT
sm->last_victim[ALLOC_NEXT] = end_segno + 1;
SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
SIT_I(sbi)->last_victim[ALLOC_NEXT] =
if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
return SIT_I(sbi)->last_victim[ALLOC_NEXT];