media: v4l: async: fix return of unitialized variable ret

A shadow declaration of variable ret is being assigned a return error
status and this value is being lost when the error exit goto's jump
out of the local scope. This leads to an uninitalized error return value
in the outer scope being returned. Fix this by removing the inner scoped
declaration of variable ret.

Detected by CoverityScan, CID#1460380 ("Uninitialized scalar variable")

Fixes: fb45f436 ("media: v4l: async: Fix notifier complete callback error handling")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/v4l2-core/v4l2-async.c

@@ -550,7 +550,6 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 		struct v4l2_device *v4l2_dev =
 			v4l2_async_notifier_find_v4l2_dev(notifier);
 		struct v4l2_async_subdev *asd;
-		int ret;
 
 		if (!v4l2_dev)
 			continue;