Fix volume stats with multiple LeftHand clusters

When more than one cluster exists in a LeftHand management
group, get_volume_stats may return the stats for the wrong
cluster. This patch fixes the problem by listing the cluster
name in the getClusterInfo query.

Change-Id: I2d5a76869c6bb1b3d514f0546ea00998e5ee32fb
Closes-Bug: #1279897
Merge "Fix volume stats with multiple LeftHand clusters"