net/mlx5e: Don't overwrite extack message returned from IPsec SA validator

Addition of new err_xfrm label caused to error messages be overwritten.
Fix it by using proper NL_SET_ERR_MSG_WEAK_MOD macro together with change
in a default message.

Fixes: aa8bd0c9 ("net/mlx5e: Support IPsec acquire default SA")
Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -712,7 +712,7 @@ static int mlx5e_xfrm_add_state(struct xfrm_state *x,
 	kfree(sa_entry->work);
 err_xfrm:
 	kfree(sa_entry);
-	NL_SET_ERR_MSG_MOD(extack, "Device failed to offload this policy");
+	NL_SET_ERR_MSG_WEAK_MOD(extack, "Device failed to offload this state");
 	return err;
 }