The uuid field in the nvme_ns structure represents the nguid field
from the identify namespace command. And as NVMe 1.3 introduced an
UUID in the NVMe Namespace Identification Descriptor this will
collide.

So rename the uuid to nguid to prevent any further
confusion. Unfortunately we export the nguid to sysfs in the uuid
sysfs attribute, but this can't be changed anymore without possibly
breaking existing userspace.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>