tty: serial: samsung: change return type for s3c24xx_serial_rx_fifocnt()

Change the return type of the s3c24xx_serial_rx_fifocnt() method to
``unsigned int`` as the method only returns the fifo size and does not
handle error codes.
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20240119104526.1221243-17-tudor.ambarus@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/samsung_tty.c

@@ -590,8 +590,8 @@ static inline const struct s3c2410_uartcfg
 	return ourport->cfg;
 }
 
-static int s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport,
-				     u32 ufstat)
+static unsigned int
+s3c24xx_serial_rx_fifocnt(const struct s3c24xx_uart_port *ourport, u32 ufstat)
 {
 	const struct s3c24xx_uart_info *info = ourport->info;