Fix syntax error in ironic-python-agent post job
Fix syntax error in ironic-python-agent post job

Using the wrong type of quotes in the bash code meant that the $ERRORS
variable wasn't being resolved, resulting in a syntax error.

Change-Id: I81c01f358338ce183dc74d4646b006fa30450473

openstack-infra/project-config,openstack-infra/project-config,Tesora/tesora-project-config,Tesora/tesora-project-config