Chore: Fix tests (#4440)

infra/vprotogen/main.go

@@ -89,12 +89,11 @@ func whichProtoc(suffix, targetedVersion string) (string, error) {
 
 	path, err := exec.LookPath(protoc)
 	if err != nil {
-		errStr := fmt.Sprintf(`
+		return "", fmt.Errorf(`
 Command "%s" not found.
 Make sure that %s is in your system path or current path.
 Download %s v%s or later from https://github.com/protocolbuffers/protobuf/releases
 `, protoc, protoc, protoc, targetedVersion)
-		return "", fmt.Errorf(errStr)
 	}
 	return path, nil
 }