net/mlx5e: fix swapped IPv6 IPsec policy masks

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: fix swapped IPv6 IPsec policy masks

IPv6 XFRM policies may use different source and destination prefix
lengths. mlx5e_ipsec_policy_mask() builds the corresponding masks
independently, but setup_fte_addr6() installs each mask in the opposite
address field.

When the prefix lengths differ, this makes the source match use the
destination prefix and the destination match use the source prefix. The
resulting hardware rule can both miss traffic covered by the policy and
match traffic outside it.

Install each mask in its corresponding match field.