ipv4: correctly iterate over the target netns in inet_dump_ifaddr()

A recent change to inet_dump_ifaddr had the function incorrectly iterate
over net rather than tgt_net, resulting in the data coming for the
incorrect network namespace.

Fixes: cdb2f80 ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Stéphane Graber <[email protected]>
Closes: lxc/incus#892
Bisected-by: Stéphane Graber <[email protected]>
Signed-off-by: Alexander Mikhalitsyn <[email protected]>
Tested-by: Stéphane Graber <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: mihalicyn

net/ipv4/devinet.c

@@ -1903,7 +1903,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 
 	cb->seq = inet_base_seq(tgt_net);
 
-	for_each_netdev_dump(net, dev, ctx->ifindex) {
+	for_each_netdev_dump(tgt_net, dev, ctx->ifindex) {
 		in_dev = __in_dev_get_rcu(dev);
 		if (!in_dev)
 			continue;