nfp: freeing the wrong variable

We accidentally free a NULL pointer and leak the pointer we want to
free.  Also you can tell from the label name what was intended.  :)

Fixes: abfcdc1de9bf ("nfp: add a stats handler for flower offloads")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/flower/metadata.c

@@ -419,7 +419,7 @@ int nfp_flower_metadata_init(struct nfp_app *app)
 	return 0;
 
 err_free_last_used:
-	kfree(priv->stats_ids.free_list.buf);
+	kfree(priv->mask_ids.last_used);
 err_free_mask_id:
 	kfree(priv->mask_ids.mask_id_free_list.buf);
 	return -ENOMEM;