media: au0828: Use umin macro

Simplifies the code.

Found by cocci:
drivers/media/usb/au0828/au0828-video.c:605:11-12: WARNING opportunity for min()

Link: https://lore.kernel.org/linux-media/20240429-fix-cocci-v3-16-3c4865f5a4b0@chromium.org
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

Author: ribalda

drivers/media/usb/au0828/au0828-video.c

@@ -602,10 +602,7 @@ static inline int au0828_isoc_copy(struct au0828_dev *dev, struct urb *urb)
 		vbi_field_size = dev->vbi_width * dev->vbi_height * 2;
 		if (dev->vbi_read < vbi_field_size) {
 			remain  = vbi_field_size - dev->vbi_read;
-			if (len < remain)
-				lencopy = len;
-			else
-				lencopy = remain;
+			lencopy = umin(len, remain);
 
 			if (vbi_buf != NULL)
 				au0828_copy_vbi(dev, vbi_dma_q, vbi_buf, p,