yanglint MAINTENANCE hide dead code

Hide part of the functionality which is not yet fully implemented.
diff --git a/tools/lint/commands.c b/tools/lint/commands.c
index bb6bf1b..58ebe96 100644
--- a/tools/lint/commands.c
+++ b/tools/lint/commands.c
@@ -461,12 +461,12 @@
     if (compiled) {
         format++;
     }
-
+#if 0
     /* tree fromat with or without gropings */
     if ((tree_opts || tree_ll) && format != LYS_OUT_TREE) {
         fprintf(stderr, "--tree options take effect only in case of the tree output format.\n");
     }
-
+#endif
     /* module, revision */
     model_name = argv[optind];
     revision = NULL;