net: change proto destroy method to return void

Change struct proto destroy function pointer to return void.  Noticed
by Al Viro.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index f44d492..1b2cea2 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -262,7 +262,7 @@
 				const struct dccp_hdr *dh, const unsigned len);
 
 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
-extern int dccp_destroy_sock(struct sock *sk);
+extern void dccp_destroy_sock(struct sock *sk);
 
 extern void		dccp_close(struct sock *sk, long timeout);
 extern struct sk_buff	*dccp_make_response(struct sock *sk,