nvme: return err on nvme_init_non_mdts_limits fail

In nvme_init_non_mdts_limits function we were returning 0 when kzalloc
failed; it now returns -ENOMEM.

Fixes: 5befc7c2 ("nvme: implement non-mdts command limits")
Signed-off-by: Joel Granados <j.granados@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>