LU-5704 utils: stop open hangs on fifo files

LU-5704 utils: stop open hangs on fifo files

Use O_NONBLOCK in open calls to prevent hangs on operations
to special files, fifo files in particular.

Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Change-Id: I20aa8425efa6ac545c3e2b970bd88e4c57c086da
Reviewed-on: http://review.whamcloud.com/19039
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>