net/mlx5: E-Switch, Fix memory leak when creating switchdev mode FDB tables

The memory allocated for the slow path table flow group input structure
was not freed upon successful return, fix that.

Fixes: 1967ce6ea5c8 ("net/mlx5: E-Switch, Refactor fast path FDB table creation in switchdev mode")
Signed-off-by: Raed Salem <raeds@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -663,6 +663,7 @@ static int esw_create_offloads_fdb_tables(struct mlx5_eswitch *esw, int nvports)
 	if (err)
 		goto miss_rule_err;
 
+	kvfree(flow_group_in);
 	return 0;
 
 miss_rule_err: