Do assert when calling relay_send_command_from_edge() on OR-side circs

src/or/relay.c

@@ -617,7 +617,7 @@ relay_send_command_from_edge_(streamid_t stream_id, circuit_t *circ,
     cell.circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
     cell_direction = CELL_DIRECTION_IN;
   } else {
-    return -1;
+    tor_assert(0);
   }
 
   memset(&rh, 0, sizeof(rh));