Add an error print in occupancy-sensing-stub.cpp

Signed-off-by: Oliver Fan <oliver.fan@nxp.com>

examples/all-clusters-app/all-clusters-common/src/occupancy-sensing-stub.cpp

@@ -71,5 +71,6 @@ void emberAfOccupancySensingClusterInitCallback(EndpointId endpointId)
     }
     else
     {
+        ChipLogError(AppServer, "Error: invalid/unexpected OccupancySensing Cluster endpoint index.");
     }
 }