V4L/DVB: hdpvr-video: cleanup signedness

The fifth parameter of usb_bulk_msg() is a pointer to signed
(see <linux/usb.h>) so also call this function with pointer to signed.

This will remove the following sparse warning (see "make C=1"):
 * warning: incorrect type in argument 5 (different signedness)
       expected int *actual_length
       got unsigned int *<noident>

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/hdpvr/hdpvr-video.c

@@ -302,7 +302,8 @@ static int hdpvr_start_streaming(struct hdpvr_device *dev)
 /* function expects dev->io_mutex to be hold by caller */
 static int hdpvr_stop_streaming(struct hdpvr_device *dev)
 {
-	uint actual_length, c = 0;
+	int actual_length;
+	uint c = 0;
 	u8 *buf;
 
 	if (dev->status == STATUS_IDLE)