quoted

IMHO we should always treat and use the
Documentation/process/license-rules.rst as the reference and not SPDX
proper who moves at its own pace and evolves its specs and license ids
independently of where we stand in the kernel.
If this is not right Doc patches are welcomed!
In this is very specific case this has been discussed on list a few
times. If I recall correctly Thomas also had an opinion on this...
So you are correct and this should be for now:
// SPDX-License-Identifier: GPL-2.0+

That is correct, stick with that format/version for now please.

OK, will fix.