tty: serial: lpc32xx_hs: Remove unused variable 'tmp'

Fixes the following W=1 kernel build warning(s):

drivers/tty/serial/lpc32xx_hs.c: In function ‘__serial_uart_flush’:
drivers/tty/serial/lpc32xx_hs.c:244:6: warning: variable ‘tmp’ set but not used [-Wunused-but-set-variable]

Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Cc: Vladimir Zapolskiy <[e-mail]>
Cc: Sylvain Lemieux <[e-mail]>
Cc: Kevin Wells <[e-mail]>
Cc: Roland Stigge <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Acked-by: Vladimir Zapolskiy <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/lpc32xx_hs.c

···
 
 static void __serial_uart_flush(struct uart_port *port)
 {
-	u32 tmp;
 	int cnt = 0;
 
 	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
 	       (cnt++ < FIFO_READ_LIMIT))
-		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
+		readl(LPC32XX_HSUART_FIFO(port->membase));
 }
 
 static void __serial_lpc32xx_rx(struct uart_port *port)