media: tvp7002: fix uninitialized variable warning

tvp7002.c: In function 'tvp7002_g_register':
tvp7002.c:691:11: warning: 'val' may be used uninitialized in this function [-Wmaybe-uninitialized]
  691 |  reg->val = val;
      |  ~~~~~~~~~^~~~~

Just return without setting 'reg' if tvp7002_read returns an error.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/tvp7002.c

@@ -688,9 +688,11 @@ static int tvp7002_g_register(struct v4l2_subdev *sd,
 	int ret;
 
 	ret = tvp7002_read(sd, reg->reg & 0xff, &val);
+	if (ret < 0)
+		return ret;
 	reg->val = val;
 	reg->size = 1;
-	return ret;
+	return 0;
 }
 
 /*