V4L/DVB (8757): v4l-dvb: fix a bunch of sparse warnings

Fixed a lot of sparse warnings: mostly warnings about shadowed variables
and signed/unsigned mismatches.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index 3461bc9..0b292ca 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -1401,7 +1401,7 @@
 	i = ret;				/* frame index */
 	frame = &gspca_dev->frame[i];
 	if (gspca_dev->memory == V4L2_MEMORY_USERPTR) {
-		if (copy_to_user((__u8 *) frame->v4l2_buf.m.userptr,
+		if (copy_to_user((__u8 __user *) frame->v4l2_buf.m.userptr,
 				 frame->data,
 				 frame->v4l2_buf.bytesused)) {
 			PDEBUG(D_ERR|D_STREAM,