MINOR: quic-stream: add qc field

Add a new member <qc> in qc_stream_desc structure. This change is
possible since previous patch which add quic-conn argument to
qc_stream_desc_new().

The purpose of this change is to simplify the future evolution of
qc-stream-desc API. This will avoid to repeat qc as argument in various
functions which already used a qc_stream_desc.

include/haproxy/quic_stream-t.h

@@ -18,6 +18,7 @@
  */
 struct qc_stream_desc {
 	struct eb64_node by_id; /* node for quic_conn tree */
+	struct quic_conn *qc;
 
 	struct buffer buf; /* buffer for STREAM data on Tx, emptied on acknowledge */
 	uint64_t ack_offset; /* last acknowledged offset */

src/quic_stream.c

@@ -28,6 +28,7 @@ struct qc_stream_desc *qc_stream_desc_new(uint64_t id, void *ctx,
 
 	stream->by_id.key = id;
 	eb64_insert(&qc->streams_by_id, &stream->by_id);
+	stream->qc = qc;
 
 	stream->buf = BUF_NULL;
 	stream->acked_frms = EB_ROOT;