Use OBJECT_STATISTICS instead of CHKOBJ for Library testing

You're currently doing this:
`QSYS/CHKOBJ OBJ(QSYS/COZTEST) OBJTYPE(*LIB) AUT(*NONE)`
To check for a library.
But you should be doing this:
```sql
select * from table(qsys2.object_statistics('QSYS','*LIB','COZTEST'))
```
That way you can remove the JOBLOG_INFO and (likely) the DLTSPLF you run and just check the results for the OBJECT_STATISTICS.