Fix a few bugs in the nginx-ingress-controller Makefile
Fix a few bugs in the nginx-ingress-controller Makefile

* make 'clean' use the new path to the built binary
* make 'container' depend on 'build'

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