Convert hwloc CPU set cpuset into the array of unsigned long mask.
mask is the array of unsigned long that will be filled. maxnode contains the maximal node number that may be stored in mask. maxnode will be set to the maximal node number that was found, plus one.
This function may be used before calling set_mempolicy, mbind, migrate_pages or any other function that takes an array of unsigned long and a maximal node number as input parameter.