OneRNG not being used by desktop running Fedora 28

[SJA]

Many thanks to Paul for his work, behind the scenes, in assisting me.  He managed to install, and use, OneRNG on a Fedora 28 VM.  Thus clearly I had a problem with my local machine.

I did a clean install and I can now I can see from the the led that OneRNG is being used when reading from /dev/random.  The device now works!

The fact that OneRNG is not listed when I run rngd -l is  a red herring - I completely misunderstood what that command was doing.

I do a have few problems with the onerng package (on Fedora 28):
* after a reboot the log shows /sbin/onerng.sh 1-1.1' failed with exit code 1 and nothing else regarding OneRNG.  The device is not being used.  This is probably some sort of race condition during boot.
* the standard rngd.service is not being killed when onerng is started.

I'm sure that I can fix these by making use of systemd.