if_awg fixes

[Kurt Jaeger]

Hi!

> I had issues with if_awg when passing heavy traffic
> (transmission, samba, ...)
[...]
> Comparing the driver against if_nfe which also uses a ring buffer,
> there are several issues with how the rings are programmed.
> I made changes inspired by it.
> 
> The following fixes improved the card behavior on my boards.
> (tested on Orange Pi PC and Orange Pi One)

Will you submit your patches via https://bugs.freebsd.org ?

Otherwise it's difficult to keep track...

-- 
pi at opsec.eu            +49 171 3101372                         3 years to go !