features/quota: log usage only if hard limit not exceeded.

Change-Id: I60abf576999996e0d0d65534e1e416f6e10994c8
Signed-off-by: Raghavendra G <rgowdapp@redhat.com>
BUG: 969461
Reviewed-on: http://review.gluster.org/6479
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>