serial: 8250: Use UART_LCR_WLEN8 instead of literal

Use UART_LCR_WLEN8 instead of literal 0x03 in size_fifo().
Reviewed-by: NJiri Slaby <jirislaby@kernel.org>
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220613075736.12283-1-ilpo.jarvinen@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_port.c

@@ -843,7 +843,7 @@ static int size_fifo(struct uart_8250_port *up)
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 	old_dl = serial_dl_read(up);
 	serial_dl_write(up, 0x0001);
-	serial_out(up, UART_LCR, 0x03);
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
 	for (count = 0; count < 256; count++)
 		serial_out(up, UART_TX, count);
 	mdelay(20);/* FIXME - schedule_timeout */