Fix NPE in LinkDiscovery

Change-Id: I4386877639fdc36dd8df26190a2cb7a3e16094e2
diff --git a/providers/lldpcommon/src/main/java/org/onosproject/provider/lldpcommon/LinkDiscovery.java b/providers/lldpcommon/src/main/java/org/onosproject/provider/lldpcommon/LinkDiscovery.java
index bea59ee..e79f58e 100644
--- a/providers/lldpcommon/src/main/java/org/onosproject/provider/lldpcommon/LinkDiscovery.java
+++ b/providers/lldpcommon/src/main/java/org/onosproject/provider/lldpcommon/LinkDiscovery.java
@@ -47,6 +47,7 @@
 
 import java.nio.ByteBuffer;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
@@ -332,7 +333,8 @@
                                                 DeviceService deviceService,
                                                 Device remoteDevice) {
         Optional<Port> remotePort = deviceService.getPorts(remoteDevice.id())
-                .stream().filter(port -> remotePortName.equals(port.annotations().value(AnnotationKeys.PORT_NAME)))
+                .stream().filter(port -> Objects.equals(remotePortName,
+                                                        port.annotations().value(AnnotationKeys.PORT_NAME)))
                 .findAny();
 
         if (remotePort.isPresent()) {