test: simplify test skipping

* Make common.skip() exit.

  Also add common.printSkipMessage() for partial skips.

* Don't make needless things before skip

PR-URL: https://github.com/nodejs/node/pull/14021
Fixes: https://github.com/nodejs/node/issues/14016
Reviewed-By: Refael Ackermann <refack@gmail.com>

test/parallel/test-https-unix-socket-self-signed.js

@@ -1,10 +1,8 @@
 'use strict';
 const common = require('../common');
 
-if (!common.hasCrypto) {
+if (!common.hasCrypto)
   common.skip('missing crypto');
-  return;
-}
 
 common.refreshTmpDir();