nbd abuses file header as a changelog (and obsolete one, too), and fails to
mention GPL.  This fixes it.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Cc: <Paul.Clements@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>