Test script test_net_ads.sh can't fail

[Isaac Boukris]

Hi,

I've submitted wip MR #765 and while working on a test, I realized it
doesn't fail when it should, right after the first call to testit(),
see:
https://gitlab.com/samba-team/samba/merge_requests/765/diffs?commit_id=28f588b18c2f13c217d958914d8cbcc0c4a7368b

Any clues on this?

Thanks,
Isaac