dind: only wait for non-sdn nodes

The 'wait-for-cluster' command of hack/dind-cluster.sh was previously
evaluating all nodes when determining whether the cluster's nodes were
seen to be 'Ready'.  The command now excludes the sdn node, whose state
is not relevant for determining cluster readiness.

hack/dind-cluster.sh

@@ -324,11 +324,12 @@ os::provision::install-cmds ${DEPLOYED_ROOT}"
 }
 
 function nodes-are-ready() {
-    local node_count=$(${DOCKER_CMD} exec -t "${MASTER_NAME}" bash -c "\
+  # Skip the SDN node since nothing is intended to be scheduled on it.
+  local node_count=$(${DOCKER_CMD} exec -t "${MASTER_NAME}" bash -c "\
 KUBECONFIG=${DEPLOYED_CONFIG_ROOT}/openshift.local.config/master/admin.kubeconfig \
-oc get nodes | grep Ready | wc -l")
-    node_count=$(echo "${node_count}" | tr -d '\r')
-    test "${node_count}" -ge "${NODE_COUNT}"
+oc get nodes | grep -v ${SDN_NODE_NAME} | grep Ready | wc -l")
+  node_count=$(echo "${node_count}" | tr -d '\r')
+  test "${node_count}" -ge "${NODE_COUNT}"
 }
 
 function wait-for-cluster() {