nvme-fc: fix numa_node when dev is null

A recent change added a numa_node field to the nvme controller
and has the transport assign the node using dev_to_node().
However, fcloop registers with a NULL device struct, so the
dev_to_node() call oops.

Revise the assignment to assign no node when device struct is null.

Fixes: 103e515e ("nvme: add a numa_node field to struct nvme_ctrl")
Reported-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
[hch: small coding style fixup]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/fc.c

@@ -3017,7 +3017,10 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 
 	ctrl->ctrl.opts = opts;
 	ctrl->ctrl.nr_reconnects = 0;
-	ctrl->ctrl.numa_node = dev_to_node(lport->dev);
+	if (lport->dev)
+		ctrl->ctrl.numa_node = dev_to_node(lport->dev);
+	else
+		ctrl->ctrl.numa_node = NUMA_NO_NODE;
 	INIT_LIST_HEAD(&ctrl->ctrl_list);
 	ctrl->lport = lport;
 	ctrl->rport = rport;