lint: provide better GPL license text test

Still not lint-stable due to too many open issues, but
at least it doesn't try to touch files that aren't part
of the repository anymore.

Change-Id: I654b15480094c7731a7d0d17fa1622a0b41ac34a
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/6584
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
1 file changed