tests: fix memory leak in test of string input visitor

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/tests/test-string-input-visitor.c b/tests/test-string-input-visitor.c
index 877e737..01a78f0 100644
--- a/tests/test-string-input-visitor.c
+++ b/tests/test-string-input-visitor.c
@@ -193,6 +193,7 @@
 
         v = visitor_input_test_init(data, buf);
         visit_type_int(v, &ires, NULL, NULL);
+        visitor_input_teardown(data, NULL);
 
         v = visitor_input_test_init(data, buf);
         visit_type_bool(v, &bres, NULL, NULL);
@@ -200,11 +201,13 @@
 
         v = visitor_input_test_init(data, buf);
         visit_type_number(v, &nres, NULL, NULL);
+        visitor_input_teardown(data, NULL);
 
         v = visitor_input_test_init(data, buf);
         sres = NULL;
         visit_type_str(v, &sres, NULL, NULL);
         g_free(sres);
+        visitor_input_teardown(data, NULL);
 
         v = visitor_input_test_init(data, buf);
         visit_type_EnumOne(v, &eres, NULL, NULL);