I was trying to replace the following statement

export DISABLE_STOP_ON_REMOVAL=yes
%service_del_preun ovsdb-server.service
%service_del_preun ovs-vswitchd.service
%service_del_preun openvswitch.service

with

%service_del_preun -n ovsdb-server.service
%service_del_preun -n ovs-vswitchd.service
%service_del_preun -n openvswitch.service

And I got the following complain from rpmlint

[   76s] openvswitch.x86_64: W: systemd-service-without-service_del_preun
openvswitch.service
[   76s] openvswitch.x86_64: W: systemd-service-without-service_del_preun
ovs-vswitchd.service
[   76s] openvswitch.x86_64: W: systemd-service-without-service_del_preun
ovsdb-server.service
[   76s] The package contains a systemd service but doesn't contain a %preun
with a
[   76s] call to service_del_preun.

However, by reading the macro source code and the openSUSE wiki, the '-n'
parameter should be a valid option so I think the rpmlint needs fixing.