tty: serial: qcom_geni_serial: Use min3 to find minimum of 3 values

Use min3 helper to calculate the minimum value of 3 variables.

Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/qcom_geni_serial.c

@@ -586,11 +586,7 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport)
 
 	avail = (port->tx_fifo_depth - port->tx_wm) * port->tx_bytes_pw;
 	tail = (xmit->tail + port->xmit_size) & (UART_XMIT_SIZE - 1);
-	if (chunk > (UART_XMIT_SIZE - tail))
-		chunk = UART_XMIT_SIZE - tail;
-	if (chunk > avail)
-		chunk = avail;
-
+	chunk = min3((size_t)chunk, (size_t)(UART_XMIT_SIZE - tail), avail);
 	if (!chunk)
 		goto out_write_wakeup;