AP_Gripper: build fix for ChibiOS

libraries/AP_Gripper/AP_Gripper_EPM.cpp

@@ -10,9 +10,10 @@
 #include "AP_Gripper_EPM.h"
 #include <AP_HAL/AP_HAL.h>
 #include <AP_BoardConfig/AP_BoardConfig.h>
+#ifdef UAVCAN_NODE_FILE
 #include <fcntl.h>
-#include <unistd.h>
-#include <cstdio>
+#include <stdio.h>
+#endif
 
 extern const AP_HAL::HAL& hal;