engine : Transaction issues in CommandsCacheImpl updateStatus

When async tasks are executed the updateCommandStatus
is being performed from two different transaction
resulting in transcation lock.

Transaction needs to be suspended before updating
command status.

Change-Id: I3e29d516b4cdf1509ae7838731869684004e5ee9
Signed-off-by: Ravi Nori <rnori@redhat.com>