video: udlfb: Improve a size determination in dlfb_alloc_urb_list()

Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/udlfb.c

@@ -1876,7 +1876,7 @@ static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
 	INIT_LIST_HEAD(&dev->urbs.list);
 
 	while (i < count) {
-		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
+		unode = kzalloc(sizeof(*unode), GFP_KERNEL);
 		if (!unode)
 			break;
 		unode->dev = dev;