metrics: Update iperf affinity

The iperf deployment is quite a lot out of date
and uses `master` for it's affinity and toleration,
so update this to control-plane, so it can run on
newer Kubernetes clusters

Signed-off-by: stevenhorsman <steven@uk.ibm.com>

tests/metrics/network/iperf3_kubernetes/runtimeclass_workloads/iperf3-daemonset.yaml

@@ -19,7 +19,7 @@ spec:
         app: iperf3-client
     spec:
       tolerations:
-        - key: node-role.kubernetes.io/master
+        - key: node-role.kubernetes.io/control-plane
           operator: Exists
           effect: NoSchedule
       containers:

tests/metrics/network/iperf3_kubernetes/runtimeclass_workloads/iperf3-deployment.yaml

@@ -25,12 +25,10 @@ spec:
           - weight: 1
             preference:
               matchExpressions:
-              - key: kubernetes.io/role
+              - key: node-role.kubernetes.io/control-plane
-                operator: In
+                operator: Exists
-                values:
-                - master
       tolerations:
-        - key: node-role.kubernetes.io/master
+        - key: node-role.kubernetes.io/control-plane
           operator: Exists
           effect: NoSchedule
       containers: