Fix for bug 677739: removing final exclusive cmirror snapshot,

Fix for bug 677739: removing final exclusive cmirror snapshot,
                    results in clvmd deadlock

When a logical volume is activated exclusively in a cluster, the
local (non-cluster-aware) target is used.  However, when creating
a snapshot on the exclusive LV, the resulting suspend/resume fails
to load the appropriate device-mapper table - instead loading the
cluster-aware target.

This patch adds an 'exclusive' parameter to the pertinent resume
functions to allow for the right target type to be loaded.