nvme-print: fix wrong list-subsys output when ns are attached to different ctrls

nvme-print: fix wrong list-subsys output when ns are attached to different ctrls

If we list subsystem controllers not for a specific ns (user did not pass
a namespace device node), we cannot look at the first ns in the subsystem
to list because it may not be attached to all subsystem controllers.

We incorrectly assumes that subsystem namespaces (or at least the first of
them) are attached to all subsystem controllers.

Fix that by showing the multipath subsystem-list flavor only when the user
passed a specific namespace, and fallback to a simple controller list otherwise.

Fixes: cdeaab8fca6e ("nvme-print: Show ANA state only for one namespace")
Fixes: 7435ed9ae6a6 ("nvme-print: Show paths from the first namespace only")
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Daniel Wagner <dwagner@suse.de>