net/mlx5: IPsec, Fix esp modify function attribute

stable inclusion
from linux-4.19.103
commit c893c6e6087ebab220ad18b16f319832821c1ae6

--------------------------------

[ Upstream commit 0dc2c534 ]

The function mlx5_fpga_esp_validate_xfrm_attrs is wrongly used
with negative negation as zero value indicates success but it
used as failure return value instead.

Fix by remove the unary not negation operator.

Fixes: 05564d0a ("net/mlx5: Add flow-steering commands for FPGA IPSec implementation")
Signed-off-by: NRaed Salem <raeds@mellanox.com>
Reviewed-by: NBoris Pismenny <borisp@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NLi Aichun <liaichun@huawei.com>
Reviewed-by: Nguodeqing <geffrey.guo@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

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

@@ -1472,7 +1472,7 @@ int mlx5_fpga_esp_modify_xfrm(struct mlx5_accel_esp_xfrm *xfrm,
 	if (!memcmp(&xfrm->attrs, attrs, sizeof(xfrm->attrs)))
 		return 0;
 
-	if (!mlx5_fpga_esp_validate_xfrm_attrs(mdev, attrs)) {
+	if (mlx5_fpga_esp_validate_xfrm_attrs(mdev, attrs)) {
 		mlx5_core_warn(mdev, "Tried to create an esp with unsupported attrs\n");
 		return -EOPNOTSUPP;
 	}