client-go: Dynamic local port not accessible when port-forwarding

When setting up a port forwarding with the client-go library (using the
`k8s.io/client-go/tools/portforward.PortForwarder`) with a non-defined local
port (i.e. passing `:80` as `ports` parameter to `portforward.New(...)`), a
local port will be assigned dynamically.

Currently, the local port will be _always_ 0 if it was not specified initially.
This is because the assigned local port is only set on a _copy_ of the actual
`ForwardedPort` type that is obtained in a `range` loop. This PR changes this
behaviour to set the local port at the correct instance by passing a pointer
instead of a copy to the relevant functions.

Kubernetes-commit: bbddd27f0dfffe6623763afe2c02c876ba925a7c

tools/portforward/portforward.go

@@ -205,8 +205,9 @@ func (pf *PortForwarder) forward() error {
 	var err error
 
 	listenSuccess := false
-	for _, port := range pf.ports {
-		err = pf.listenOnPort(&port)
+	for i := range pf.ports {
+		port := &pf.ports[i]
+		err = pf.listenOnPort(port)
 		switch {
 		case err == nil:
 			listenSuccess = true