Fix example test suites without result

generated by testing/codegen.

Author: tchssk

testing/codegen/templates/suite_test.go.tpl

@@ -15,7 +15,7 @@ func Run{{ .Service.StructName }}Harness(t *testing.T, svc {{ .Service.PkgName }
 {{- range .NonStream }}
 	{{- $m := . }}
 	t.Run("{{ $m.Method.Name }}", func(t *testing.T) {
-		result, err := h.Client.{{ $m.Method.VarName }}({{ if $.UseCtx }}ctx{{ else }}context.Background(){{ end }}{{- if $m.Method.PayloadEx }}, td.Valid{{ goify $m.Method.Name true }}Payload(){{ end }})
+		{{ if $m.Method.ResultRef }}result, {{ end }}err := h.Client.{{ $m.Method.VarName }}({{ if $.UseCtx }}ctx{{ else }}context.Background(){{ end }}{{- if $m.Method.PayloadEx }}, td.Valid{{ goify $m.Method.Name true }}Payload(){{ end }})
 		if err != nil {
 			t.Errorf("{{ $m.Method.Name }} failed: %v", err)
 		}

testing/codegen/testdata/code.go

@@ -948,7 +948,7 @@ func RunWithoutResultServiceHarness(t *testing.T, svc withoutresultservice.Servi
 
 	td := withoutResultServicetest.NewTestData()
 	t.Run("WithoutResultMethod", func(t *testing.T) {
-		result, err := h.Client.WithoutResultMethod(ctx)
+		err := h.Client.WithoutResultMethod(ctx)
 		if err != nil {
 			t.Errorf("WithoutResultMethod failed: %v", err)
 		}