test: skip the test with proper TAP message

On Windows, the test simply returns which will be counted as passed.
The test actually skips the rest of the test. So proper TAP message has
to be included while skipping.

This patch uses `common.skip` rather than `console.log` to print the
skip messages.

PR-URL: nodejs/node#11584
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/parallel/test-setproctitle.js

@@ -4,8 +4,7 @@ const common = require('../common');
 
 // FIXME add sunos support
 if (!(common.isFreeBSD || common.isOSX || common.isLinux)) {
- console.log(`1..0 # Skipped: Unsupported platform [${process.platform}]`);
- return;
+ return common.skip(`Unsupported platform [${process.platform}]`);
 }
 
 const assert = require('assert');