test: fix flaky test-net-socket-timeout

Fixes: https://github.com/nodejs/node/issues/5892
PR-URL: https://github.com/nodejs/node/pull/5902
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-net-socket-timeout.js

@@ -41,7 +41,7 @@ server.listen(common.PORT, function() {
   });
   var timer = setTimeout(function() {
     process.exit(1);
-  }, 200);
+  }, common.platformTimeout(200));
 });
 
 process.on('exit', function() {