Don't talk about the LGPL if the file is licensed under the GPL

Some files claim that the code is licensed under the GPL, but then
suddenly suggest that the user should have a look at the LGPL.
That's of course non-sense, replace it with the correct GPL wording
instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1548255083-8190-1-git-send-email-thuth@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>