nvmet: don't look at the request_queue in nvmet_bdev_zone_mgmt_emulate_all

nvmet is a consumer of the block layer and should not directly look at
the request_queue.  Just use the NUMA node ID from the gendisk instead of
the request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>