yanglint FEATURE do not load ietf-yang-library by default

To avoid validation errors caused by this module.
Fixes #1371
diff --git a/tools/lint/cmd_data.c b/tools/lint/cmd_data.c
index e2cd6fd..a78f06b 100644
--- a/tools/lint/cmd_data.c
+++ b/tools/lint/cmd_data.c
@@ -62,8 +62,9 @@
             "  -m, --merge   Merge input data files into a single tree and validate at\n"
             "                once.The option has effect only for 'data' and 'config' TYPEs.\n"
             "                In case of using -x option, the data are always merged.\n"
-            "  -s, --strict  Strict data parsing (do not skip unknown data), has no effect\n"
-            "                for schemas.\n"
+            "  -n, --not-strict\n"
+            "                Do not require strict data parsing (silently skip unknown data),\n"
+            "                has no effect for schemas.\n\n"
             "  -O FILE, --operational=FILE\n"
             "                Provide optional data to extend validation of the 'rpc',\n"
             "                'reply' or 'notif' TYPEs. The FILE is supposed to contain\n"