__list_for_each - iterate over a list
__list_for_each (pos, head);
pos the &struct list_head to use as a loop counter. head the head for your list.
This variant differs from list_for_each in that it’s the simplest possible list iteration code, no prefetching is done. Use this for code that knows the list to be very short (empty or 1 entry) most of the time.