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/sctp/socket.c b/net/sctp/socket.c
index 253e5ea..f98650c 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3588,7 +3588,7 @@
 }
 
 /* Cleanup any SCTP per socket resources.  */
-SCTP_STATIC int sctp_destroy_sock(struct sock *sk)
+SCTP_STATIC void sctp_destroy_sock(struct sock *sk)
 {
 	struct sctp_endpoint *ep;
 
@@ -3598,7 +3598,6 @@
 	ep = sctp_sk(sk)->ep;
 	sctp_endpoint_free(ep);
 	atomic_dec(&sctp_sockets_allocated);
-	return 0;
 }
 
 /* API 4.1.7 shutdown() - TCP Style Syntax