MFC r329370, r330239: Rationalize license text on Linuxolator files

Many licenses on Linuxolator files contained small variations from the
standard FreeBSD license text. To avoid license proliferation switch to
the standard 2-clause FreeBSD license for those files where I have
permission from each of the listed copyright holders.

Approved by: dchagin, kan, marcel, rdivacky, sos
Sponsored by: The FreeBSD Foundation