[PATCH] nss_files: Fix /etc/aliases null pointer dereference [BZ #24059]

[Florian Weimer]

* Adhemerval Zanella:

> What is preventing the tests to work with test-in-container by copying
> the lib in the chroot?

For test-in-container, I'm still trying to figure out how to reliably
re-run a test after a test update, without having to wait five minutes
or more, until a rebuild from nothing completes.

Thanks,
Florian