nvme: remove unused parameter

First parameter of nvme_init_integrity() is unused.
Remove it, and modify the callers.

Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>