nfp: check the right pointer for errors

Correct checking error condition on wrong pointer -
copy/paste mistake most likely.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c

@@ -200,7 +200,7 @@ void nfp_net_debugfs_adapter_add(struct nfp_net *nn)
 
 	/* Create queue debugging sub-tree */
 	queues = debugfs_create_dir("queue", nn->debugfs_dir);
-	if (IS_ERR_OR_NULL(nn->debugfs_dir))
+	if (IS_ERR_OR_NULL(queues))
 		return;
 
 	rx = debugfs_create_dir("rx", queues);