jsafrane: Fixed ControllerUnpublish error handling

JobBuild
165
08-06 08:37
pull-kubernetes-csi-external-attacher-1-13-on-kubernetes-1-13 1159373066078261248 1158768462890274820 1158765571043495938 1158658363374964737
pull-kubernetes-csi-external-attacher-1-14-on-kubernetes-1-14 1159373066078261250 1158768462890274818 1158765571043495936 1158716241041428480 1158658363374964738
pull-kubernetes-csi-external-attacher-1-15-on-kubernetes-1-15 1159373066078261249 1158768462890274816 1158765571043495937 1158658363374964739
pull-kubernetes-csi-external-attacher-unit 1159373066078261251 1158768462890274817 1158765571043495939 1158658363374964736