AP_GPS: helper func

libraries/AP_GPS/AP_GPS.cpp

@@ -432,13 +432,11 @@ void AP_GPS::detect_instance(uint8_t instance)
             return;
         }
         for (uint8_t i = 0; i < MAX_NUMBER_OF_CAN_DRIVERS; i++) {
-            if (hal.can_mgr[i] == nullptr) {
-                continue;
-            }
-            AP_UAVCAN *uavcan = hal.can_mgr[i]->get_UAVCAN();
-            if (uavcan == nullptr) {
+            AP_UAVCAN *ap_uavcan = AP_UAVCAN::get_uavcan(i);
+            if (ap_uavcan == nullptr) {
                 continue;
             }
+            
             uint8_t gps_node = uavcan->find_gps_without_listener();
             if (gps_node == UINT8_MAX) {
                 continue;

libraries/AP_GPS/AP_GPS_UAVCAN.cpp

@@ -37,15 +37,14 @@ AP_GPS_UAVCAN::AP_GPS_UAVCAN(AP_GPS &_gps, AP_GPS::GPS_State &_state, AP_HAL::UA
 // For each instance we need to deregister from AP_UAVCAN class
 AP_GPS_UAVCAN::~AP_GPS_UAVCAN()
 {
-    if (hal.can_mgr[_manager] == nullptr) {
-        return;
-    }
-    AP_UAVCAN *ap_uavcan = hal.can_mgr[_manager]->get_UAVCAN();
+    AP_UAVCAN *ap_uavcan = AP_UAVCAN::get_uavcan(_manager);
     if (ap_uavcan == nullptr) {
         return;
     }
-
+    
     ap_uavcan->remove_gps_listener(this);
+    delete _sem_gnss;
+    
     debug_gps_uavcan(2, "AP_GPS_UAVCAN destructed\n\r");
 }