opt_mitosis: fixed type for variable "slice": BUN iso. oid
opt_mitosis: fixed type for variable "slice": BUN iso. oid

For record counts, we use C type BUN, not oid.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb