fix coredump

Signed-off-by: Nhaozi007 <liuhao27@huawei.com>

src/image/oci/storage/layer_store/layer_store.c

@@ -733,6 +733,7 @@ static int insert_digest_into_map(map_t *by_digest, const char *digest, const ch
             ERROR("Out of memory");
             return -1;
         }
+        linked_list_init(&(new_list->layer_list));
         old_list = new_list;
     }