The sysfs group containing the cmb attributes is registered before the
driver knows if they need to be visible or not. Update the group when
cmb attributes are known to exist so the visibility setting is correct.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217037
Fixes: 86adbf0c ("nvme: simplify transport specific device attribute handling")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>