Licensing of mq_open_tests.c

[Thomas Gleixner <tglx@xxxxxxxxxxxxx>]

Folks!

The file tools/testing/selftests/mqueue/mq_open_tests.c which was
authored by Doug is licensed under GPLv3 only.

While this is a user space program it includes a GPLv2 only kernel
header (kselftest.h), which results in a license conflict.

So one of both needs to be relicensed.

Thanks,

        tglx