svcrdma: Update synopsis of svc_rdma_send_reply_msg()

Preparing for subsequent patches, no behavior change expected.

Pass the RPC Call's svc_rdma_recv_ctxt deeper into the sendto()
path. This enables passing more information about Requester-
provided Write and Reply chunks into those lower-level functions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

net/sunrpc/xprtrdma/svc_rdma_sendto.c

@@ -729,13 +729,12 @@ static void svc_rdma_save_io_pages(struct svc_rqst *rqstp,
  */
 static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma,
 				   struct svc_rdma_send_ctxt *sctxt,
-				   struct svc_rdma_recv_ctxt *rctxt,
-				   struct svc_rqst *rqstp,
-				   __be32 *wr_lst, __be32 *rp_ch)
+				   const struct svc_rdma_recv_ctxt *rctxt,
+				   struct svc_rqst *rqstp)
 {
 	int ret;
 
-	if (!rp_ch) {
+	if (!rctxt->rc_reply_chunk) {
 		ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt,
 					     &rqstp->rq_res);
 		if (ret < 0)
@@ -856,8 +855,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
 	}
 
 	svc_rdma_sync_reply_hdr(rdma, sctxt, svc_rdma_reply_hdr_len(rdma_resp));
-	ret = svc_rdma_send_reply_msg(rdma, sctxt, rctxt, rqstp,
-				      wr_lst, rp_ch);
+	ret = svc_rdma_send_reply_msg(rdma, sctxt, rctxt, rqstp);
 	if (ret < 0)
 		goto err1;
 	ret = 0;