Fix for the Reconcile loop is not exitting properly

[mpryc]

Fixes issue #65

Whenever we want to exit with error state from the reconcile loop that is considered final state we should use TerminalError.

Returning standard error will cause Reconcile to requeue.

Testing

1. Deploy controller without the change
2. Create NonAdminBackup without proper backupSpec, for example

apiVersion: nac.oadp.openshift.io/v1alpha1
kind: NonAdminBackup
metadata:
  name: example
  namespace: nacproject
spec: {}

3. Observe controller log. It will show error, however it will re-enter check every few seconds.

With this fix, the point number 3 will not re-enter check every few seconds.

In either scenario proper NonAdminBackup object phase and conditions are correct.

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mpryc, shubham-pampattiwar

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [mpryc,shubham-pampattiwar]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[shubham-pampattiwar]

/lgtm