AP_UAVCAN: fixed build with no GCS

Co-authored-by: Peter Barker <pbarker@barker.dropbear.id.au>

libraries/AP_UAVCAN/AP_UAVCAN.cpp

@@ -332,6 +332,7 @@ void AP_UAVCAN::init(uint8_t driver_index, bool enable_filters)
 // send ESC telemetry messages over MAVLink
 void AP_UAVCAN::send_esc_telemetry_mavlink(uint8_t mav_chan)
 {
+#ifndef HAL_NO_GCS
     static const uint8_t MAV_ESC_GROUPS = 3;
     static const uint8_t MAV_ESC_PER_GROUP = 4;
 
@@ -398,6 +399,7 @@ void AP_UAVCAN::send_esc_telemetry_mavlink(uint8_t mav_chan)
                 break;
         }
     }
+#endif // HAL_NO_GCS
 }
 
 void AP_UAVCAN::loop(void)

libraries/AP_UAVCAN/AP_UAVCAN_DNA_Server.cpp

@@ -638,7 +638,7 @@ void AP_UAVCAN_DNA_Server::handleAllocation(uint8_t driver_index, uint8_t node_i
                     msg.node_id = resp_node_id;
                 }
             } else {
-                gcs().send_text(MAV_SEVERITY_ERROR, "UC Node Alloc Failed!");
+                GCS_SEND_TEXT(MAV_SEVERITY_ERROR, "UC Node Alloc Failed!");
             }
         } else {
             msg.node_id = resp_node_id;