vrf: use dev_replace_track() for better tracking

vrf_rt6_release() and vrf_rtable_release() changes dst->dev

Instead of

dev_hold(ndev);
dev_put(odev);

We should use

dev_replace_track(odev, ndev, &dst->dev_tracker, GFP_KERNEL);

If we do not transfer dst->dev_tracker to the new device,
we will get warnings from ref_tracker_dir_exit() when odev
is finally dismantled.

Fixes: 9038c320 ("net: dst: add net device refcount tracking to dst_entry")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211207055603.1926372-1-eric.dumazet@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/vrf.c

@@ -814,9 +814,9 @@ static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
 	 */
 	if (rt6) {
 		dst = &rt6->dst;
-		dev_put(dst->dev);
+		dev_replace_track(dst->dev, net->loopback_dev,
+				  &dst->dev_tracker, GFP_KERNEL);
 		dst->dev = net->loopback_dev;
-		dev_hold(dst->dev);
 		dst_release(dst);
 	}
 }
@@ -1061,9 +1061,9 @@ static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
 	 */
 	if (rth) {
 		dst = &rth->dst;
-		dev_put(dst->dev);
+		dev_replace_track(dst->dev, net->loopback_dev,
+				  &dst->dev_tracker, GFP_KERNEL);
 		dst->dev = net->loopback_dev;
-		dev_hold(dst->dev);
 		dst_release(dst);
 	}
 }