rpm: simplify daemon-reload trigger

The trigger was initially written to use %transfiletriggerun instead
of %transfiletriggerpostun because the latter would not fire. It turned
out to a buffer overread in rpm that since has been long fixed:
https://bugzilla.redhat.com/show_bug.cgi?id=1284645
https://github.com/rpm-software-management/rpm/commit/f6521c50f6836374a0f7995f8f393aaf36e178ea