ffs_appleufs_cksum
ffs_appleufs_cksum(appleufsblk.b_un.b_appleufs); \
appleufs->ul_checksum = ffs_appleufs_cksum(appleufs);
appleufs->ul_checksum = ffs_appleufs_cksum(appleufs);
n->ul_checksum = ffs_appleufs_cksum(n);
u_int16_t ffs_appleufs_cksum(const struct appleufslabel *);