BUG/MINOR: mux-quic: fix possible infinite loop during decoding

With the support of multiple Rx buffers per QCS instance, stream
decoding in qcc_io_recv() has been reworked for the next haproxy
release. An issue appears in a double while loop : a break statement is
used in the inner loop, which is not sufficient as it should instead
exit from the outer one.

Fix this by replacing break with a goto statement.

No need to backport this.

src/mux_quic.c

@@ -2952,10 +2952,11 @@ static int qcc_io_recv(struct qcc *qcc)
 			LIST_DEL_INIT(&qcs->el_recv);
 
 			if (ret <= 0)
-				break;
+				goto done;
 		}
 	}
 
+ done:
 	TRACE_LEAVE(QMUX_EV_QCC_RECV, qcc->conn);
 	return 0;
 }