usb: gadget: s3c: remove unused 'udc' variable

Remove unused 'udc' variable to fix compile warnings:

    drivers/usb/gadget/udc/s3c2410_udc.c: In function 's3c2410_udc_dequeue':
    drivers/usb/gadget/udc/s3c2410_udc.c:1268:22: warning: variable 'udc' set but not used [-Wunused-but-set-variable]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20200731074122.6484-1-krzk@kernel.org

drivers/usb/gadget/udc/s3c2410_udc.c

@@ -1265,7 +1265,6 @@ static int s3c2410_udc_queue(struct usb_ep *_ep, struct usb_request *_req,
 static int s3c2410_udc_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 {
 	struct s3c2410_ep	*ep = to_s3c2410_ep(_ep);
-	struct s3c2410_udc	*udc;
 	int			retval = -EINVAL;
 	unsigned long		flags;
 	struct s3c2410_request	*req = NULL;
@@ -1278,8 +1277,6 @@ static int s3c2410_udc_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 	if (!_ep || !_req)
 		return retval;
 
-	udc = to_s3c2410_udc(ep->gadget);
-
 	local_irq_save(flags);
 
 	list_for_each_entry(req, &ep->queue, queue) {