net/mlx5: IPsec, fix memory leak at mlx5_fpga_ipsec_delete_sa_ctx

SA context is allocated at mlx5_fpga_ipsec_create_sa_ctx,
however the counterpart mlx5_fpga_ipsec_delete_sa_ctx function
nullifies sa_ctx pointer without freeing the memory allocated,
hence the memory leak.

Fix by free SA context when the SA is released.

Fixes: d6c4f029 ("net/mlx5: Refactor accel IPSec code")
Signed-off-by: Raed Salem <raeds@mellanox.com>
Reviewed-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c

@@ -850,6 +850,7 @@ void mlx5_fpga_ipsec_delete_sa_ctx(void *context)
 	mutex_lock(&fpga_xfrm->lock);
 	if (!--fpga_xfrm->num_rules) {
 		mlx5_fpga_ipsec_release_sa_ctx(fpga_xfrm->sa_ctx);
+		kfree(fpga_xfrm->sa_ctx);
 		fpga_xfrm->sa_ctx = NULL;
 	}
 	mutex_unlock(&fpga_xfrm->lock);