KRNL-5820: Add support for openSUSE's alternative security/limits.conf path

[rfrohl]

Is your feature request related to a problem? Please describe. openSUSE distros (MicroOS, Tumbleweed) provide an alternative way to update the system, called atomic updates. Part of this feature are alternative paths for config files under /usr/etc.

Describe the solution you'd like KRNL-5730 should be able to detect limits.conf in none default locations, like /usr/etc/security/limits.conf.

Required changes KRNL-5730 needs to check under /usr/etc/security/ for a limits.conf too.

Additional context Details about the move to /usr/etc

https://kubic.opensuse.org/blog/2019-12-05-usr-etc/

[rfrohl]

Posted a suggested change, please let me know if it would require changes.

testing this change currently in the openSUSE infra, local tests look good so far.