net/mlx5e: Replace zero-length arrays with DECLARE_FLEX_ARRAY() helper

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations in anonymous union with the new DECLARE_FLEX_ARRAY() helper macro.

This helper allows for flexible-array members in unions.

---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 48241317a535..0db41fa4a9a6 100644
@@ -97,8 +97,8 @@ struct mlx5_flow_attr {
 	} lag;
 	/* keep this union last */
 	union {
-		struct mlx5_esw_flow_attr esw_attr[0];
-		struct mlx5_nic_flow_attr nic_attr[0];
+		DECLARE_FLEX_ARRAY(struct mlx5_esw_flow_attr, esw_attr);
+		DECLARE_FLEX_ARRAY(struct mlx5_nic_flow_attr, nic_attr);
 	};
 };
 

2.34.1