test MAINTENANCE for printer tree

Based on pyang update (version 2.4.0).
Comments have also been clarified.
diff --git a/tests/utests/schema/test_printer_tree.c b/tests/utests/schema/test_printer_tree.c
index eee35f4..e678cbf 100644
--- a/tests/utests/schema/test_printer_tree.c
+++ b/tests/utests/schema/test_printer_tree.c
@@ -1481,7 +1481,7 @@
             "  }\n"
             "}\n";
 
-    /* from pyang but edited -> n1 node is moved to n2 */
+    /* from pyang */
     expect =
             "module: a24\n"
             "  +--rw top\n"
@@ -1749,7 +1749,8 @@
             "  container mont;\n"
             "}\n";
 
-    /* from pyang but with these adjustments:
+    /* from pyang (--tree-print-yang-data --tree-print-groupings -p "...")
+     * but with these adjustments:
      *  - <flags> is always '--' for yang-data nodes
      *  - yang-data tmp3 has two 'uses' nodes
      *  - grouping g2 has ':' character at the end
@@ -1788,7 +1789,8 @@
 
     ly_out_reset(UTEST_OUT);
 
-    /* from pyang but with these adjustments:
+    /* from pyang (--tree-print-yang-data -p "...")
+     * but with these adjustments:
      *  <flags> is always '--' for yang-data nodes
      */
     expect =