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/bt8xx/bttv-risc.c b/drivers/media/video/bt8xx/bttv-risc.c
index 649682a..5b1b8e4 100644
--- a/drivers/media/video/bt8xx/bttv-risc.c
+++ b/drivers/media/video/bt8xx/bttv-risc.c
@@ -244,7 +244,8 @@
 		  const struct bttv_format *fmt, struct bttv_overlay *ov,
 		  int skip_even, int skip_odd)
 {
-	int dwords,rc,line,maxy,start,end,skip,nskips;
+	int dwords, rc, line, maxy, start, end;
+	unsigned skip, nskips;
 	struct btcx_skiplist *skips;
 	__le32 *rp;
 	u32 ri,ra;