Fix error check in examples/custom-controller
Fix error check in examples/custom-controller

Fixes #669

nevetS/ingress,kubernetes/ingress-nginx,matthewg/ingress,canhnt/ingress,canhnt/ingress,nicksardo/ingress,chentao1596/ingress,caicloud/ingress,danielqsj/ingress,caicloud/ingress,jcmoraisjr/ingress,canhnt/ingress,aledbf/ingress-nginx,literalice/ingress,winfield-chen-hs/ingress,coryfklein/ingress,nicksardo/ingress,kubernetes/ingress-nginx,jcmoraisjr/ingress,kubernetes/ingress-nginx,kubernetes/ingress-gce,aledbf/ingress-nginx,caiyixiang/ingress,aledbf/ingress-nginx,arjanschaaf/ingress,literalice/ingress,nicksardo/ingress,kubernetes/ingress-nginx,caiyixiang/ingress,aledbf/ingress-nginx,nevetS/ingress,matthewg/ingress,danielqsj/ingress,jcmoraisjr/ingress,winfield-chen-hs/ingress,kubernetes/ingress-nginx,arjanschaaf/ingress,caicloud/ingress,caicloud/ingress,chentao1596/ingress,nicksardo/ingress,canhnt/ingress,coryfklein/ingress,kubernetes/ingress-gce