dmu_free_long_object
err = dmu_free_long_object(rwa->os, drro->drr_object);
err = dmu_free_long_object(rwa->os, slot);
err = dmu_free_long_object(rwa->os, obj);
free_err = dmu_free_long_object(rwa.os, obj);
(void) dmu_free_long_object(os, obj);
int dmu_free_long_object(objset_t *os, uint64_t object);