ipv6: Fix the link time qualifier of 'ping_v6_proc_exit_net()'

[ Upstream commit d23dbc479a8e813db4161a695d67da0e36557846 ]

The '.exit' functions from 'pernet_operations' structure should be marked
as __net_exit, not __net_init.

Fixes: d862e54 ("net: ipv6: Implement /proc/net/icmp6.")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/ipv6/ping.c

@@ -233,7 +233,7 @@ static int __net_init ping_v6_proc_init_net(struct net *net)
 	return ping_proc_register(net, &ping_v6_seq_afinfo);
 }
 
-static void __net_init ping_v6_proc_exit_net(struct net *net)
+static void __net_exit ping_v6_proc_exit_net(struct net *net)
 {
 	return ping_proc_unregister(net, &ping_v6_seq_afinfo);
 }