AP_UAVCAN: make all semaphores recursive

the cost is very similar and this prevents an easy coding error which
can occur on less used code paths

libraries/AP_UAVCAN/AP_UAVCAN_DNA_Server.h

@@ -82,7 +82,7 @@ class AP_UAVCAN_DNA_Server
     //Look in the storage and check if there's a valid Server Record there
     bool isValidNodeDataAvailable(uint8_t node_id);
 
-    HAL_Semaphore_Recursive sem;
+    HAL_Semaphore sem;
 
 public:
     AP_UAVCAN_DNA_Server(StorageAccess _storage) : storage(_storage) {}