License change

[Joachim Kuebart]

Hi,

much to my embarrassment, I noticed recently that there is a file
authored by me using the 4-clause BSD license in the FreeBSD tree. The
file src/sys/dev/sound/pci/es137x.c uses the 4-clause BSD license while
the accompanying .h file uses a kind of 3-clause BSD license that I
apparently made up at the time.

I would like to change the license of es137x.c to the 3-clause BSD
license. Unfortunately I cannot prove that I'm in fact the original
author because the e-mail address given in the file is no longer active.
If this means that the license cannot be changed anymore, that's
unfortunate, but I guess it's the way it has to be...

Best regards,

Joachim