net/mlx5e: fix double free in macsec_fs_tx_create_crypto_table_groups

In function macsec_fs_tx_create_crypto_table_groups(), when the ft->g
memory is successfully allocated but the 'in' memory fails to be
allocated, the memory pointed to by ft->g is released once. And in function
macsec_fs_tx_create(), macsec_fs_tx_destroy() is called to release the
memory pointed to by ft->g again. This will cause double free problem.

Fixes: e467b283 ("net/mlx5e: Add MACsec TX steering rules")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec_fs.c

@@ -161,6 +161,7 @@ static int macsec_fs_tx_create_crypto_table_groups(struct mlx5e_flow_table *ft)
 
 	if (!in) {
 		kfree(ft->g);
+		ft->g = NULL;
 		return -ENOMEM;
 	}