Comment # 1 on bug 935834 from Martin Pluskal

Well how about uninstalling systemd-logger? It's just dummy package - from
describtion: "This package marks the installation to not use syslog but only
the journal."

# rpm -ql systemd-logger
/var/log/README
/var/log/journal

In other words you can safely choose solution 1 offered by zypper to achieve
what you want.