posix: system_database_r: remove invalid compilation filters

[cfriedt]

The files pwd.c and grp.c both had incorrect preprocessor guards around the stubs that they were implementing. Functions were surrounded by

#ifdef CONFIG_POSIX_THREAD_SAFE_FUNCTIONS
..
#endif

which is not at all accurate, since that subprofiling option group is (CONFIG_)POSIX_SYSTEM_DATABASE_R.

https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_subprofiles.html

Remove the guards, since they are invalid anyway, and at least allow applications to link properly.

Required by #88547

[JarmouniA]

Looks like the commit message is unrelated the actual change, unless I'm missing something.

[cfriedt]

@JarmouniA - I forgot to fill in a part of the commit message, but it is the right one. Let me update

Edit: oh, actually - the #ifdef lines were stripped from the commit message. That's why it looks like something is missing.

[cfriedt]

For reference, the PRs that will add POSIX_SYSTEM_DATABASE and POSIX_SYSTEM_DATABASE_R functionality are below.
#84859
#84858

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[JarmouniA]

We don't really need the guards anyway, since conditional compilation will be used to link the files into the build.

Are you referring to this?

zephyr/lib/posix/options/CMakeLists.txt

Line 142 in 1e85543

zephyr_library_sources_ifdef(CONFIG_POSIX_THREADS

[cfriedt]

We don't really need the guards anyway, since conditional compilation will be used to link the files into the build.

Are you referring to this?

Not exactly. This from #84858

if (NOT CONFIG_TC_PROVIDES_POSIX_SYSTEM_DATABASE_R)
  zephyr_library_sources_ifdef(CONFIG_POSIX_SYSTEM_DATABASE_R
    system_database_priv.c
    system_database_r.c
  )
endif()