Previously, we simply checked $? which at that point would be the exit
status of echo, not openstack-ansible. By recording the actual
openstack-ansible exit status, we can properly report failures of the
upgrade script.
Closes-bug: 1480342
Change-Id: Icf43bea84660e4160a2dfcdb4ac93055340b3573
(cherry picked from commit 8a106d184a566f1baed616aee7747d5f2d581c1b)