xhci: use max() to make code cleaner

Use max() in order to make code cleaner.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Link: https://lore.kernel.org/r/20211215091602.445009-1-deng.changcheng@zte.com.cnSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci.c

@@ -4998,10 +4998,8 @@ static int calculate_max_exit_latency(struct usb_device *udev,
 			enabling_u2)
 		u2_mel_us = DIV_ROUND_UP(udev->u2_params.mel, 1000);
 
-	if (u1_mel_us > u2_mel_us)
-		mel_us = u1_mel_us;
-	else
-		mel_us = u2_mel_us;
+	mel_us = max(u1_mel_us, u2_mel_us);
+
 	/* xHCI host controller max exit latency field is only 16 bits wide. */
 	if (mel_us > MAX_EXIT) {
 		dev_warn(&udev->dev, "Link PM max exit latency of %lluus "