st_change_block_size
rval = st_change_block_size(un, 0);
rval = st_change_block_size(un, 0);
static int st_change_block_size(struct scsi_tape *un, uint32_t nblksz);
if (st_change_block_size(un, (uint32_t)mtop->mt_count) != 0) {
if (st_change_block_size(un, 0) != 0) {
} else if (st_change_block_size(un, 0) == 0) {
if (st_change_block_size(un, 0) == 0) {
ST_FUNC(ST_DEVINFO, st_change_block_size);