logparser.py: don't error out on exec events without target
commit 7297e2f6 assumed that exec events always have a "target=...", but this is only true for events in complain mode. In enforce mode, the log line doesn't include "target=...".
This commits sets an empty target instead of erroring out on every exec event in enforce mode.
Also adjust ask_exec() in aa.py to only update hashlog[aamode][target_profile]['final_name']
if target_profile is set (hashlog[aamode]['']
doesn't exist and trying to write to it would error out)
Also add log testcases for exec with and without target=
- in complain mode, exec events include target=...
- in enforce mode, the log message doesn't include target=...
Note that the utils tests skip exec events (they'd be interactive), therefore exec*.profile doesn't contain an exec rule.
Manual testing shows that setting an empty target works as expected.