[media] saa7164: fix compiler warning

build/media_build/v4l/saa7164-core.c: In function 'saa7164_initdev':
build/media_build/v4l/saa7164-core.c:1192:6: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int err, i;
        ^
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/pci/saa7164/saa7164-core.c

@@ -1196,7 +1196,8 @@ static int saa7164_initdev(struct pci_dev *pci_dev,
 	if (NULL == dev)
 		return -ENOMEM;
 
-	if (v4l2_device_register(&pci_dev->dev, &dev->v4l2_dev)) {
+	err = v4l2_device_register(&pci_dev->dev, &dev->v4l2_dev);
+	if (err < 0) {
 		dev_err(&pci_dev->dev, "v4l2_device_register failed\n");
 		goto fail_free;
 	}