use err==nil in tcc callbranch

dtmgrpc/tcc.go

@@ -75,16 +75,15 @@ func TccFromGrpc(ctx context.Context) (*TccGrpc, error) {
 func (t *TccGrpc) CallBranch(busiMsg proto.Message, tryURL string, confirmURL string, cancelURL string, reply interface{}) error {
 	branchID := t.NewSubBranchID()
 	bd, err := proto.Marshal(busiMsg)
-	if err != nil {
-		return err
+	if err == nil {
+		_, err = dtmgimp.MustGetDtmClient(t.Dtm).RegisterBranch(context.Background(), &dtmgpb.DtmBranchRequest{
+			Gid:         t.Gid,
+			TransType:   t.TransType,
+			BranchID:    branchID,
+			BusiPayload: bd,
+			Data:        map[string]string{"confirm": confirmURL, "cancel": cancelURL},
+		})
 	}
-	_, err = dtmgimp.MustGetDtmClient(t.Dtm).RegisterBranch(context.Background(), &dtmgpb.DtmBranchRequest{
-		Gid:         t.Gid,
-		TransType:   t.TransType,
-		BranchID:    branchID,
-		BusiPayload: bd,
-		Data:        map[string]string{"confirm": confirmURL, "cancel": cancelURL},
-	})
 	if err != nil {
 		return err
 	}