libxl_json: remove extra "break"

... otherwise JSON array elements are not freed and memory is leaked.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
(cherry picked from commit 3eb54a2fdb)

tools/libxl/libxl_json.c

@@ -285,7 +285,6 @@ void libxl__json_object_free(libxl__gc *gc, libxl__json_object *obj)
     }
     case JSON_ARRAY: {
         libxl__json_object *node = NULL;
-        break;
 
         for (idx = 0; idx < obj->u.array->count; idx++) {
             if (flexarray_get(obj->u.array, idx, (void**)&node) != 0)