OpenStack: fix controlPlanePort validation

When the controlPlanePort has no network defined, we attempt to
validate the network using the empty name and id, this results
in multiple networks found, which breaks the pre-flight validation
resulting in it being skipped. This commit fixed the issue, by only
running validation on that field if it has content defined.

pkg/asset/installconfig/openstack/validation/cloudinfo.go

@@ -185,7 +185,8 @@ func (ci *CloudInfo) collectInfo(ic *types.InstallConfig, opts *clientconfig.Cli
 		if err != nil {
 			return err
 		}
-		ci.ControlPlanePortNetwork, err = ci.getNetwork(controlPlanePort.Network.Name, controlPlanePort.Network.ID)
+
+		ci.ControlPlanePortNetwork, err = ci.getNetwork(controlPlanePort)
 		if err != nil {
 			return err
 		}
@@ -317,10 +318,18 @@ func (ci *CloudInfo) getNetworkByName(networkName string) (*networks.Network, er
 	return network, nil
 }
 
-func (ci *CloudInfo) getNetwork(networkName, networkID string) (*networks.Network, error) {
-	opts := networks.ListOpts{
-		ID:   networkID,
-		Name: networkName,
+func (ci *CloudInfo) getNetwork(controlPlanePort *openstack.PortTarget) (*networks.Network, error) {
+	networkName := controlPlanePort.Network.Name
+	networkID := controlPlanePort.Network.ID
+	if networkName == "" && networkID == "" {
+		return nil, nil
+	}
+	opts := networks.ListOpts{}
+	if networkID != "" {
+		opts.ID = controlPlanePort.Network.ID
+	}
+	if networkName != "" {
+		opts.Name = controlPlanePort.Network.Name
 	}
 	allPages, err := networks.List(ci.clients.networkClient, opts).AllPages()
 	if err != nil {