nvme: send Identify with CNS 06h only to I/O controllers

Identify CNS 06h (I/O Command Set Specific Identify Controller data
structure) is supported only on i/o controllers.

But nvme_init_non_mdts_limits() currently invokes this on all
controllers.  Correct this by ensuring this is sent to I/O
controllers only.
Signed-off-by: Martin George <marting@netapp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -3063,7 +3063,8 @@ static int nvme_init_non_mdts_limits(struct nvme_ctrl *ctrl)
 	else
 		ctrl->max_zeroes_sectors = 0;
 
-	if (nvme_ctrl_limited_cns(ctrl))
+	if (ctrl->subsys->subtype != NVME_NQN_NVME ||
+	    nvme_ctrl_limited_cns(ctrl))
 		return 0;
 
 	id = kzalloc(sizeof(*id), GFP_KERNEL);