yanglint TEST for --ext-data by schema mount
diff --git a/tools/lint/tests/data/modsm.xml b/tools/lint/tests/data/modsm.xml
new file mode 100644
index 0000000..bb0793c
--- /dev/null
+++ b/tools/lint/tests/data/modsm.xml
@@ -0,0 +1,3 @@
+<root xmlns="urn:yanglint:modsm">
+  <lfl xmlns="urn:yanglint:modleaf">7</lfl>
+</root>