Merge pull request #46907 from zhangxiaoyu-zidif/add-comment-for-genutils

Automatic merge from submit-queue (batch tested with PRs 46787, 46876, 46621, 46907, 46819)

Add fatal message

**What this PR does / why we need it**:
Add fatal message

**Release note**:

```release-note
NONE
```

cmd/genutils/genutils_test.go

@@ -30,13 +30,13 @@ func TestValidDir(t *testing.T) {
 func TestInvalidDir(t *testing.T) {
 	_, err := OutDir("./nondir")
 	if err == nil {
-		t.Fatal(err)
+		t.Fatal("expected an error")
 	}
 }
 
 func TestNotDir(t *testing.T) {
 	_, err := OutDir("./genutils_test.go")
 	if err == nil {
-		t.Fatal(err)
+		t.Fatal("expected an error")
 	}
 }