small issue with ->private method

While writing Coro::Event I stumbled over a very small issue. I created
events using calls similar to these:

   $w = Event->io(private => $q, ...);

but never got anything back from the private method except undef. I can
now only make a quick guess that private, which uses the caller's package,
sees some other package (probably Event itself) when using it while
initalizing the watcher.

As such the fix was easy:

   $w = Event->io(...);
   $w->private($q);

If it's eay to fix I'd say fix it. If a fix would make private slower I'd
say document this and don't fix it ;)

-- 
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      ----==-- _                                           |
      ---==---(_)__  __ ____  __       Marc Lehmann      +--
      --==---/ / _ \/ // /\ \/ /       [email protected]      |e|
      -=====/_/_//_/\_,_/ /_/\_\       XX11-RIPE         --+
    The choice of a GNU generation                       |
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