UPSTREAM: <carry>: fix calculation of max cluster size

When scaling up, the calculation for the maximum size of the cluster
based on `--max-nodes-total` doesn't take into account any nodes that
are in the process of coming up. This allows the cluster to grow
beyond the size specified.

With this change I now see:

scale_up.go:266] 21 other pods are also unschedulable
scale_up.go:423] Best option to resize: openshift-cluster-api/amcdermo-ca-worker-us-east-2b
scale_up.go:427] Estimated 18 nodes needed in openshift-cluster-api/amcdermo-ca-worker-us-east-2b
scale_up.go:432] Capping size to max cluster total size (23)
static_autoscaler.go:275] Failed to scale up: max node total count already reached

cluster-autoscaler/core/scale_up.go

@@ -434,7 +434,7 @@ func ScaleUp(context *context.AutoscalingContext, processors *ca_processors.Auto
 
 		if context.MaxNodesTotal > 0 && len(nodes)+newNodes > context.MaxNodesTotal {
 			klog.V(1).Infof("Capping size to max cluster total size (%d)", context.MaxNodesTotal)
-			newNodes = context.MaxNodesTotal - len(nodes)
+			newNodes = context.MaxNodesTotal - len(nodes) - len(upcomingNodes)
 			if newNodes < 1 {
 				return &status.ScaleUpStatus{Result: status.ScaleUpError}, errors.NewAutoscalerError(
 					errors.TransientError,