cli: More checks in rebalance status output

Change-Id: Ibd2edc5608ae6d3370607bff1c626c8347c4deda
BUG: 1031887
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/6561
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>