[Piglit] no fcntl module on Windows

[Brian Paul]

The recent commit

commit 21031482e7a9fc828622ea2015d87432704b1c7f
Author: Olivier Berthier <olivierx.berthier at linux.intel.com>
Date:   Mon May 2 13:05:17 2016 +0200

     framework: Add aborting option when a monitored error is detected

causes a problem on Windows.  There's no fcntl module.  It's imported by 
the new framework/monitoring.py file.  I suspect there's additional 
Windows issues besides that, but that's the first thing that fails.

Can this functionality be limited to Linux so we don't break Windows?

-Brian