Check correct label value when setting protocl hint (linkerd#5267)

This fixes an issue where the protocol hint is always set on endpoint responses.
We now check the right value which determines if the pod has the required label.

A test for this has been added to linkerd#5266.

Signed-off-by: Kevin Leimkuhler <kevin@kleimkuhler.com>

controller/api/destination/endpoint_translator.go

@@ -307,7 +307,7 @@ func toWeightedAddr(address watcher.Address, enableH2Upgrade bool, identityTrust
 	// If the pod is controlled by any Linkerd control plane, then it can be hinted
 	// that this destination knows H2 (and handles our orig-proto translation).
 	var hint *pb.ProtocolHint
-	if enableH2Upgrade && controllerNS != "" {
+	if enableH2Upgrade && controllerNSLabel != "" {
 		hint = &pb.ProtocolHint{
 			Protocol: &pb.ProtocolHint_H2_{
 				H2: &pb.ProtocolHint_H2{},