nvme: always unregister the integrity profile in __nvme_revalidate_disk

This is safe because the queue is always frozen when we revalidate, and
it simplifies both the existing code as well as the multipath
implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>