YANG parser CHANGE ommit module parse fail message when parsing submodule file

submodules cannot be parsed separately, keep the error message about
this the only message printed, so ommit the general "Module parsing failed."
diff --git a/src/parser_yang.c b/src/parser_yang.c
index 8a27bb3..e908917 100644
--- a/src/parser_yang.c
+++ b/src/parser_yang.c
@@ -2606,7 +2606,12 @@
 
     ret = yang_parse_mem(module, NULL, unres, data, size, &node);
     if (ret == -1) {
-        free_yang_common(module, node);
+        if (ly_vecode == LYVE_SUBMODULE) {
+            free(module);
+            module = NULL;
+        } else {
+            free_yang_common(module, node);
+        }
         goto error;
     } else if (ret == 1) {
         assert(!unres->count);