Fix Sonar critical flagged bugs

Change-Id: I60e9f72a1a66f65366d7dbc5335922e75097c9f3
diff --git a/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/GrpcDeviceUtils.java b/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/GrpcDeviceUtils.java
index 7045b0c..aaf1e0b 100644
--- a/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/GrpcDeviceUtils.java
+++ b/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/GrpcDeviceUtils.java
@@ -65,6 +65,7 @@
             return MastershipRole.STANDBY;
         case UNRECOGNIZED:
             log.warn("Unrecognized MastershipRole gRPC message: {}", role);
+            return MastershipRole.NONE;
         default:
             return MastershipRole.NONE;
         }