net/mlx5: fs, an FTE should have no dests when deleted

When deleting an FTE it should have no dests, which means
fte->dests_size should be 0. Add a WARN_ON() to catch bugs
where the proper tracking wasn't done.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/fs_core.c

@@ -605,6 +605,7 @@ static void del_hw_fte(struct fs_node *node)
 	fs_get_obj(ft, fg->node.parent);
 
 	trace_mlx5_fs_del_fte(fte);
+	WARN_ON(fte->dests_size);
 	dev = get_dev(&ft->node);
 	root = find_root(&ft->node);
 	if (node->active) {