Clarify detection of GPL with BSD disclaimers

[pombredanne]

Description

Some GPL exist in the Linux kernel with a BSD-like disclaimer. We detect them alright but it would be nice to have some indication that there may be also some BSD-like disclaimer

See
https://lore.kernel.org/linux-spdx/alpine.DEB.2.21.1905201027400.24434@nanos.tec.linutronix.de/T/#ebb8dac1ad77f818ff0bc68407326829368dc4e95

Reported-by: @swinslow

[pombredanne]

In the case of https://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-spdx.git/tree/drivers/scsi/a100u2w.c?id=750afb08ca71310fcf0c4e2cb1565c63b8235b60
there was another BSD derivative in older code circa the Git migration https://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-spdx.git/commit/drivers/scsi/a100u2w.c?id=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2

It was removed by Alan Cox and James Bottomley with https://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-spdx.git/commit/drivers/scsi/a100u2w.c?id=4023c4747861e8c56f46e5fa50bd4feb63fc91fc

[pombredanne]

For reference the BSD in question is this one: https://github.com/nexB/scancode-toolkit/blob/40e7192f71f3a9b9822aeba44441d08b67736a7a/src/licensedcode/data/licenses/bsd-top-gpl-addition.LICENSE

[pombredanne]

In the case of https://lore.kernel.org/linux-spdx/alpine.DEB.2.21.1905201027400.24434@nanos.tec.linutronix.de/T/#m3268e97c076a0cad3b321a31c1a18b919c2991b5

The commit log [1] shows this was clearly always this way and is original code [2]
People do funky stuff at times and mix and match notices and disclaimers from various origins.
So this is IMHO a GPL alright and there is no BSD in play.

The legal question is whether such a disclaimer would need to be kept or not.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-spdx.git/log/drivers/net/can/slcan.c
[2] https://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-spdx.git/commit/drivers/net/can/slcan.c?id=a1044e36e457fb6dbdf90ce756d578b251d99b5e