nvme: show subsys nqn for duplicate cntlids

The driver assigned nvme handle isn't persistent across reboots, so is
not enough information to match up where the collisions are occuring.
Add the subsys nqn string to the output so that it can more easily be
identified later.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215099
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>