nvlist_add_descriptor_array
nvlist_add_descriptor_array(nvl, key, in_array, count);
nvlist_add_descriptor_array(nvl, key, desc, nitems(desc));
nvlist_add_descriptor_array(nvl, key, fd, nitems(fd));
nvlist_add_descriptor_array(src, "nvl/fd", testfd, nitems(testfd));
nvlist_add_descriptor_array(nvl, "nvl/fd", NULL, 0);
nvlist_add_descriptor_array(nvl, "nvl/fd", fdadd, 1);
void nvlist_add_descriptor_array(nvlist_t *nvl, const char *name, const int *value, size_t nitems);
nvlist_add_descriptor_array(nvl_filed, "f_addr_fds",