nbd: Remove fixme that was already fixed
nbd: Remove fixme that was already fixed

The mentioned problem is not present anymore.

Signed-off-by: Markus Pargmann <b9e0f7aed71fa470d5913fb2df2da788a8fb0eb2@pengutronix.de>
Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@fb.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs