core: Fence via second power management not work...

Fence via second power management not working

Adding a check for status 'unknown", if we get this status we can be
sure that agent definitions are corrupted and exit the wait for status
loop.
Fixing the way the dual sequential agents work by reseting the executor
object to perform the original operation (actually recreating it with
the correct action before handling the other secondary agent)

Change-Id: I97c05e96e2c8d5f690addda61e0dd577c423ff07
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=982604
Signed-off-by: root <emesika@redhat.com>