card_uart_tx: Remove last argument (we always have the receiver active)

Change-Id: I8f82e9108d0eae86bbe4535403ccc680b7379a0e
diff --git a/ccid_host/cuart_driver_tty.c b/ccid_host/cuart_driver_tty.c
index 7fc8d3a..3695b58 100644
--- a/ccid_host/cuart_driver_tty.c
+++ b/ccid_host/cuart_driver_tty.c
@@ -220,7 +220,7 @@
 	return 0;
 }
 
-static int tty_uart_async_tx(struct card_uart *cuart, const uint8_t *data, size_t len, bool rx_after)
+static int tty_uart_async_tx(struct card_uart *cuart, const uint8_t *data, size_t len)
 {
 	OSMO_ASSERT(cuart->driver == &tty_uart_driver);