quota/marker: Fix dict leaks

Unref dicts in quota and marker functions before they return.

Change-Id: I772edc7b46657a70fb136e037576c65e9beeaca8
BUG: 1139327
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/8655
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Tested-by: Raghavendra G <rgowdapp@redhat.com>