glusterd: coverity fix for overrun in glusterd_stop_uds_listener

CID: 1260432

Change-Id: I6845bc4c231b53428419a5a2ad0c78ea9da31058
BUG: 1093692
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-on: http://review.gluster.org/9338
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>