[PATCH] nvme: add nvme_is_disc_subsys() helper

[Christoph Hellwig]

On Thu, Oct 22, 2026 at 01:01:44PM +0530, Martin George wrote:
> Mirror the target's nvmet_is_disc_subsys() with a host-side
> nvme_is_disc_subsys() helper, and use it for the open-coded
> subtype == NVME_NQN_DISC checks in the host code to help
> maintain consistency and improve code readability.
> 
> And while here, fix an error message to refer to the subsystem
> rather than the controller.

Not going to NAK it, but the helper feels a bit pointless to me.
Do you have any bigger plans with it?