[Positioner] AccessPoint: avoid division by zero

owlps-positioner/src/accesspoint.cc

@@ -71,6 +71,9 @@ received_calibration_from_ap(const AccessPoint &trx) const
       expected_packets += (*cr)->get_nb_packets() ;
     }
 
+  if (expected_packets == 0)
+    return 0 ;
+
   // Compute the score (percent):
   float score = received_packets * 100.0 / expected_packets ;
   return score ;