net/mlx5e: Warn when destroying mod hdr hash table that is not empty

To avoid memory leaks add a warn when destroying mod hdr hash table
but the hash table is not empty.

Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en/mod_hdr.c

@@ -47,6 +47,7 @@ void mlx5e_mod_hdr_tbl_init(struct mod_hdr_tbl *tbl)
 
 void mlx5e_mod_hdr_tbl_destroy(struct mod_hdr_tbl *tbl)
 {
+	WARN_ON(!hash_empty(tbl->hlist));
 	mutex_destroy(&tbl->lock);
 }