lib: merge 'undefined' into one 'break' branch

We don't need to split this alone, but just merge it into the 'break'
switch branch together.

PR-URL: #26039
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/main/print_help.js

@@ -65,6 +65,7 @@ function getArgDescription(type) {
     case 'kNoOp':
     case 'kV8Option':
     case 'kBoolean':
+    case undefined:
       break;
     case 'kHostPort':
       return '[host:]port';
@@ -73,8 +74,6 @@ function getArgDescription(type) {
     case 'kString':
     case 'kStringList':
       return '...';
-    case undefined:
-      break;
     default:
       require('assert').fail(`unknown option type ${type}`);
   }