Description of problem:
The build push prints a "Successfully pushed" message even if the actual image push fails.

Version-Release number of selected component (if applicable):
v4u7

How reproducible:
Easy

Steps to Reproduce:

---
$ oc patch configs.imageregistry.operator.openshift.io/cluster --patch '{"spec":{"managementState":"Managed"}}' --type=merge

$ oc new-project foo

$ cat < EOF | oc create -f -
apiVersion: image.openshift.io/v1
kind: ImageStream
metadata:
  name: busybox
---
apiVersion: v1
kind: BuildConfig
metadata:
  name: busybox
spec:
  output:
    to:
      kind: ImageStreamTag
      name: busybox:latest
  source:
    type: Dockerfile
    dockerfile: |-
      FROM k8s.gcr.io/busybox
      ENTRYPOINT ["sleep", "6000"]
  strategy:
    dockerStrategy:
      from:
        kind: DockerImage
        name: k8s.gcr.io/busybox
    type: Docker
  triggers:
  - imageChange: {}
    type: ImageChange
EOF

$ oc start-build busybox --wait=true --follow=true
---

Actual results:
The output print a "Successfully pushed" message even if the image push fails.

---
Pushing image image-registry.openshift-image-registry.svc:5000/foo/busybox:latest ...
Getting image source signatures
Successfully pushed image-registry.openshift-image-registry.svc:5000/foo/busybox:latest
Warning: Push failed, retrying in 5s ...
Getting image source signatures
Successfully pushed image-registry.openshift-image-registry.svc:5000/foo/busybox:latest
Warning: Push failed, retrying in 5s ...
Getting image source signatures
Successfully pushed image-registry.openshift-image-registry.svc:5000/foo/busybox:latest
Warning: Push failed, retrying in 5s ...
error: build error: Failed to push image: error copying layers and metadata from "containers-storage:[overlay@/var/lib/containers/storage+/var/run/containers/storage:overlay.imagestore=/var/lib/shared]image-registry.openshift-image-registry.svc:5000/foo/busybox:latest" to "docker://image-registry.openshift-image-registry.svc:5000/foo/busybox:latest": Error trying to reuse blob sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4 at destination: error pinging docker registry image-registry.openshift-image-registry.svc:5000: Get "https://image-registry.openshift-image-registry.svc:5000/v2/": dial tcp: lookup image-registry.openshift-image-registry.svc on 172.30.0.10:53: no such host
---

Expected results:
It should not print a "Successfully pushed" message.

Additional info: