vm: fix formatting

vm/gc.cpp

@@ -77,8 +77,9 @@ void factor_vm::garbage_collection(cell collecting_gen_, bool growing_data_heap_
 		{
 			current_gc->growing_data_heap = true;
 
-                        /* see the comment in unmark_marked() */
-                        code->unmark_marked();
+			/* Since we start tracing again, any previously
+			marked code blocks must be re-marked and re-traced */
+			code->clear_mark_bits();
 		}
 		/* we try collecting aging space twice before going on to
 		collect tenured */