This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
We were inconsitently using them in some cases, but in majority not.
Using assignment in assert_se is very common, not an exception like in
'if', so let's drop the extra parens everywhere.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
test-dlopen is a very simple binary that is only linked with libc and
libdl. From it we do dlopen() on the nss and pam modules to check that they are
linked to all necessary libs.
(meson-compiled nss modules are linked to less libraries, for whatever reason.
I suspected that some deps are missing, but it turns out that my suspicions
weren't justified, and the modules load just fine. Let's keep the test though,
it is very quick, and might detect missing linkage in the future.)
