cluster/afr: Add descriptions to message-ids.

Change-Id: I7ec2821c96d4cbff78b4959d9b07019896cc9a2c
BUG: 1075611
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/7840
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: N Balachandran <nbalacha@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com>