glusterd: Store rebalance state on all peers

The rebalance state was being saved only on the peers participating in
the rebalance on a rebalance start. This change makes sure all nodes
save the rebalance state.

Change-Id: I436e5c34bcfb88f7da7378cec807328ce32397bc
BUG: 1157979
Signed-off-by: Kaushal M <kaushal@redhat.com>
Reviewed-on: http://review.gluster.org/8998
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>