MINOR: quic: Add the number of TX bytes to traces

This should be helpful to diagnose some issues regarding packet loss
and recovery issues.
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index f9d61e2..61ba70d 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -305,7 +305,9 @@
 					chunk_appendf(&trace_buf, " pn=%llu",(ull)pkt->pn_node.key);
 				list_for_each_entry(frm, &pkt->frms, list)
 					chunk_frm_appendf(&trace_buf, frm);
-				chunk_appendf(&trace_buf, " tx.bytes=%llu", (unsigned long long)qc->tx.bytes);
+				chunk_appendf(&trace_buf, " rx.bytes=%llu tx.bytes=%llu",
+				              (unsigned long long)qc->rx.bytes,
+				              (unsigned long long)qc->tx.bytes);
 			}
 
 			if (room) {