Fix check for overcloud compute hostname
Fix check for overcloud compute hostname

The overcloud compute hostname is actually overcloud-novacompute0-xxxxx,
so the extra dash here was failing the check.  This should hopefully
resolve the latest CD cloud failure.

Change-Id: I6dace6a34b79170a88aa571141bb3cb52ba08027

rdo-management/tripleo,rdo-management/tripleo