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 <stgraber@stgraber.org>
Closes: lxc/incus#892
Bisected-by: Stéphane Graber <stgraber@stgraber.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Tested-by: Stéphane Graber <stgraber@stgraber.org>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240528203030.10839-1-aleksandr.mikhalitsyn@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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;