Silently ignore devices without gNMI client

It is an indication that the device is not gNMI-enabled

Change-Id: Iede116cb839cb58c533dc709a50cc0f469f0997a
diff --git a/protocols/p4runtime/ctl/src/main/java/org/onosproject/p4runtime/ctl/P4RuntimeControllerImpl.java b/protocols/p4runtime/ctl/src/main/java/org/onosproject/p4runtime/ctl/P4RuntimeControllerImpl.java
index a287653..ac1d90f 100644
--- a/protocols/p4runtime/ctl/src/main/java/org/onosproject/p4runtime/ctl/P4RuntimeControllerImpl.java
+++ b/protocols/p4runtime/ctl/src/main/java/org/onosproject/p4runtime/ctl/P4RuntimeControllerImpl.java
@@ -17,7 +17,6 @@
 package org.onosproject.p4runtime.ctl;
 
 import com.google.common.collect.Maps;
-import com.google.common.util.concurrent.Striped;
 import io.grpc.ManagedChannel;
 import org.onosproject.grpc.ctl.AbstractGrpcClientController;
 import org.onosproject.net.DeviceId;
@@ -39,7 +38,6 @@
 
 import java.math.BigInteger;
 import java.util.concurrent.ConcurrentMap;
-import java.util.concurrent.locks.Lock;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static org.slf4j.LoggerFactory.getLogger;
@@ -57,7 +55,6 @@
 
     private final ConcurrentMap<DeviceId, ConcurrentMap<ProviderId, DeviceAgentListener>>
             deviceAgentListeners = Maps.newConcurrentMap();
-    private final Striped<Lock> stripedLocks = Striped.lock(30);
 
     private DistributedElectionIdGenerator electionIdGenerator;
 
diff --git a/providers/general/device/src/main/java/org/onosproject/provider/general/device/impl/GnmiDeviceStateSubscriber.java b/providers/general/device/src/main/java/org/onosproject/provider/general/device/impl/GnmiDeviceStateSubscriber.java
index 028c5fb..6e164bf 100644
--- a/providers/general/device/src/main/java/org/onosproject/provider/general/device/impl/GnmiDeviceStateSubscriber.java
+++ b/providers/general/device/src/main/java/org/onosproject/provider/general/device/impl/GnmiDeviceStateSubscriber.java
@@ -155,7 +155,7 @@
 
         GnmiClient client = gnmiController.getClient(deviceId);
         if (client == null) {
-            log.warn("Cannot find gNMI client for device {}", deviceId);
+            log.debug("Cannot find gNMI client for device {}, ignoring.", deviceId);
             return;
         }