Incorrect logger initialisation

Loggers for the driver and the approver are currently ultimately created by [`klog.TODO`](https://pkg.go.dev/k8s.io/klog/v2#TODO) in [this section of code](https://github.com/cert-manager/csi-driver-spiffe/blob/17ff261113d759f54808b96aeeeee45359291ebb/internal/flags/flags.go#L71).

The flow control here is confusing and could be improved, and TODO is also documented as a "last resort".