LU-8658 ptlrpc: Suppress error for flock requests

LU-8658 ptlrpc: Suppress error for flock requests

-EAGAIN is a normal return when requesting POSIX flocks.
We can't recognize exactly that case here, but it's the
only case that should result in -EAGAIN on LDLM_ENQUEUE, so
don't print to console in that case.

Signed-off-by: Patrick Farrell <paf@cray.com>
Change-Id: Idfbaf671023ac2c3dc84ddd62d2e547427b1f50b
Reviewed-on: http://review.whamcloud.com/22856
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>