set_open_status

[Ken Brown]

Most fhandlers call set_open_status in their 'open' method before a successful 
return.  I just noticed that fhandler_fifo::open doesn't do this.  I thought at 
first that it was an oversight on my part from when I overhauled the FIFO 
implementation, but I just checked fhandler_fifo.cc as of cygwin 2.9.0, and I 
don't see it there either.

Is there some reason this would be wrong for FIFOs?

Ken