Store file descriptor of the logger file (RhBug:1594016)

[j-mracek]

https://bugzilla.redhat.com/show_bug.cgi?id=1594016

[j-mracek]

I am really sorry, but I do not know how the merge was pushed.

[lukash]

Well 🙂

One think I would welcome is some description of what this is meant to do.

So, the sack_dealloc is being called correctly, but the log_out pointer wasn't stored, so it couldn't close it, right?

Retroactively, LGTM.

But, it doesn't seem great that the logging FD is opened multiple times per one run of the application depending on how the sack is used. It should be opened once in the beginning and closed at the end.