The third argument of the pad-chain-pre and pad-chain-post hooks are of type GstBuffer* and GstBufferList* respectively. However, when I added do_chain_buffer_pre() and do_chain_buffer_post() to gstlog.c I accidentally make them take GstFlowReturn -- almost certainly as an artifact from duplicating the code of the _post() variants, leading to erroneous log lines like this: ``` do_chain_buffer_pre:<vp9parse0:sink> 0:00:01.615378540, pad=<vp9parse0:sink>, res=-1073639680 ``` This patch fixes that. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8366>