Update failure and unstack_installation_status()

[h wulff]

Hi!

We use the SWupdate API for external programs and we struggle with
information of the failure in case of a FAILURE.

Mainly we've the same problem like this last post:

> https://groups.google.com/g/swupdate/c/_ao7by3Uvfs/m/6ykwyj18AwAJ

We'd a look into

> swupdate/ipc//network_ipc-if.c

and it turns out that

> unstack_installation_status()

gets called in good case only. In bad case, when jumping to label
"out", the call to unstack_installation_status() is skipped.

Is there a reason to do so? It is even more interesting to get the
status messages in bad case.

Thanks.
--
h.wulff