Remove mapped_mod when done

passes/techmap/abc9.cc

@@ -937,6 +937,8 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 		//log("ABC RESULTS:        internal signals: %8d\n", int(signal_list.size()) - in_wires - out_wires);
 		log("ABC RESULTS:           input signals: %8d\n", in_wires);
 		log("ABC RESULTS:          output signals: %8d\n", out_wires);
+
+		design->remove(mapped_mod);
 	}
 	//else
 	//{