media: sun6i-csi: bridge: Error out on invalid port to fix warning

The enabled variable is only set for a valid port and used later,
which triggers an uninitialized use smatch warning. Explicitly error
out in that case to fix the warning.
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Fixes: 0d2b746b ("media: sun6i-csi: Add bridge v4l2 subdev with port management")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_bridge.c

@@ -663,7 +663,7 @@ sun6i_csi_bridge_notifier_bound(struct v4l2_async_notifier *notifier,
 		enabled = !bridge->source_parallel.expected;
 		break;
 	default:
-		break;
+		return -EINVAL;
 	}
 
 	source->subdev = remote_subdev;