Having the ctrl name "nvmeX" seems much more friendly than
the underlying device name. Also, with other nvme transports
such as the soon to come nvme-loop we don't have an underlying
device so it doesn't makes sense to make up one.

In order to help matching an instance name to a pci function,
we add a info print in nvme_probe.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Acked-by: NKeith Busch <keith.busch@intel.com>

Manually fixed up the hunk in nvme_cancel_queue_ios().
Signed-off-by: NJens Axboe <axboe@fb.com>