[PATCH] nbd: kill obsolete changelog, add GPL

nbd abuses file header as a changelog (and obsolete one, too), and fails to
mention GPL.  This fixes it.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: <Paul.Clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>