List: enable LIST_HEAD_FORMAT for -r option

Currently, the LIST_HEAD_FORMAT is not set, 'list -r' will list the
traversal results in order, not in the reverse order. This is not
the expected behavior.

Let's enable the LIST_HEAD_FORMAT for -r option by default.

Signed-off-by: Li Zhijian <[email protected]>

tools.c

@@ -3370,6 +3370,7 @@ cmd_list(void)
 			break;
 
 		case 'r':
+			ld->flags |= LIST_HEAD_FORMAT;
 			ld->flags |= LIST_HEAD_REVERSE;
 			break;