tty: serial: samsung: return bool for s3c24xx_serial_txempty_nofifo()

s3c24xx_serial_txempty_nofifo() returned either 0 or BIT(2), which is
counterintuitive. Make the method return bool, and return true when TX
is empty and false otherwise.
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20240119104526.1221243-15-tudor.ambarus@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/samsung_tty.c

@@ -236,7 +236,7 @@ static inline const char *s3c24xx_serial_portname(const struct uart_port *port)
 	return to_platform_device(port->dev)->name;
 }
 
-static int s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
+static bool s3c24xx_serial_txempty_nofifo(const struct uart_port *port)
 {
 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
 }
@@ -782,7 +782,7 @@ static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
 		ch = rd_reg(port, S3C2410_URXH);
 
 		if (port->flags & UPF_CONS_FLOW) {
-			int txe = s3c24xx_serial_txempty_nofifo(port);
+			bool txe = s3c24xx_serial_txempty_nofifo(port);
 
 			if (ourport->rx_enabled) {
 				if (!txe) {