nvme: don't use nvme_update_disk_info for the multipath disk

Currently nvme_update_ns_info_block calls nvme_update_disk_info both for
the namespace attached disk, and the multipath one (if it exists).  This
is very different from how other stacking drivers work, and leads to
a lot of complexity.

Switch to setting the disk capacity and initializing the integrity
profile, and let blk_stack_limits which already is called just below
deal with updating the other limits.

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