cluster/afr: Fix leaks in self-heal code path

Change-Id: I5301ec9ebac27afe52e85cad75e6395d7f891355
BUG: 1120151
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/8316
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>