helper/args: copy args on wt creation

Signed-off-by: Ophestra <cat@gensokyo.uk>

dbus/dbus_test.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"os/exec"
 	"strings"
+	"syscall"
 	"testing"
 	"time"
 
@@ -71,7 +72,7 @@ func TestProxy_Seal(t *testing.T) {
 	for id, tc := range testCasePairs() {
 		t.Run("create seal for "+id, func(t *testing.T) {
 			p := dbus.New(tc[0].bus, tc[1].bus)
-			if err := p.Seal(tc[0].c, tc[1].c); (errors.Is(err, helper.ErrContainsNull)) != tc[0].wantErr {
+			if err := p.Seal(tc[0].c, tc[1].c); (errors.Is(err, syscall.EINVAL)) != tc[0].wantErr {
 				t.Errorf("Seal(%p, %p) error = %v, wantErr %v",
 					tc[0].c, tc[1].c,
 					err, tc[0].wantErr)