net: spread __net_init, __net_exit

__net_init/__net_exit are apparently not going away, so use them
to full extent.

In some cases __net_init was removed, because it was called from
__net_exit code.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index f0126fd..4f7d212 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2027,12 +2027,12 @@
 	},
 };
 
-static int udp4_proc_init_net(struct net *net)
+static int __net_init udp4_proc_init_net(struct net *net)
 {
 	return udp_proc_register(net, &udp4_seq_afinfo);
 }
 
-static void udp4_proc_exit_net(struct net *net)
+static void __net_exit udp4_proc_exit_net(struct net *net)
 {
 	udp_proc_unregister(net, &udp4_seq_afinfo);
 }