Fix crash caused by resouce discovery failed

pkg/informers/informers.go

@@ -17,6 +17,7 @@ limitations under the License.
 package informers
 
 import (
+	"reflect"
 	"time"
 
 	snapshotclient "github.com/kubernetes-csi/external-snapshotter/client/v4/clientset/versioned"
@@ -51,6 +52,11 @@ type InformerFactory interface {
 	Start(stopCh <-chan struct{})
 }
 
+type GenericInformerFactory interface {
+	Start(stopCh <-chan struct{})
+	WaitForCacheSync(stopCh <-chan struct{}) map[reflect.Type]bool
+}
+
 type informerFactories struct {
 	informerFactory              k8sinformers.SharedInformerFactory
 	ksInformerFactory            ksinformers.SharedInformerFactory