features/snapview-client: handle fsync fop

Change-Id: Idaf46bd7497266af837789b09a0c62698f56ee4e
BUG: 1172262
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.org/9258
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Sachin Pandit <spandit@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>