test: fix racey-ness in tls-inception

Fix test failure on FreeBSD and SmartOS, which happens due to a bad
timing:

    events.js:141
          throw er; // Unhandled 'error' event
                ^
    Error: read ECONNRESET
        at exports._errnoException (util.js:734:11)
        at TLSWrap.onread (net.js:538:26)

The outer `net.conncet()` socket stays alive after the inner socket is
gone. This happens because `.pipe()`'s implementation does not `destroy`
the source side when the destination has emitted `close`.

Fix: https://github.com/iojs/io.js/issues/1012
PR-URL: https://github.com/iojs/io.js/pull/1040


Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>