[UNIX]: Extend unix_sysctl_(un)register prototypes

Add the struct net * argument to both of them to use in
the future. Also make the register one return an error code.

It is useless right now, but will make the future patches
much simpler.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/unix/sysctl_net_unix.c b/net/unix/sysctl_net_unix.c
index eb0bd57..b2e0407 100644
--- a/net/unix/sysctl_net_unix.c
+++ b/net/unix/sysctl_net_unix.c
@@ -48,12 +48,13 @@
 
 static struct ctl_table_header * unix_sysctl_header;
 
-void unix_sysctl_register(void)
+int unix_sysctl_register(struct net *net)
 {
 	unix_sysctl_header = register_sysctl_table(unix_root_table);
+	return unix_sysctl_header == NULL ? -ENOMEM : 0;
 }
 
-void unix_sysctl_unregister(void)
+void unix_sysctl_unregister(struct net *net)
 {
 	unregister_sysctl_table(unix_sysctl_header);
 }