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/dccp/ipv4.c b/net/dccp/ipv4.c
index dad7bc4..b195c4f 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -996,7 +996,7 @@
 	.flags		= INET_PROTOSW_ICSK,
 };
 
-static int dccp_v4_init_net(struct net *net)
+static int __net_init dccp_v4_init_net(struct net *net)
 {
 	int err;
 
@@ -1005,7 +1005,7 @@
 	return err;
 }
 
-static void dccp_v4_exit_net(struct net *net)
+static void __net_exit dccp_v4_exit_net(struct net *net)
 {
 	inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
 }