SUNRPC: create stubs for xprtsock init and cleanup

Over time we will want to add some specific init and cleanup logic for the
xprtsock implementation.  Add stub routines for initialization and exit
processing.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/sunrpc_syms.c

@@ -138,6 +138,8 @@ EXPORT_SYMBOL(nlm_debug);
 extern int register_rpc_pipefs(void);
 extern void unregister_rpc_pipefs(void);
 extern struct cache_detail ip_map_cache;
+extern int init_socket_xprt(void);
+extern void cleanup_socket_xprt(void);
 
 static int __init
 init_sunrpc(void)
@@ -155,6 +157,7 @@ init_sunrpc(void)
 	rpc_proc_init();
 #endif
 	cache_register(&ip_map_cache);
+	init_socket_xprt();
 out:
 	return err;
 }
@@ -162,6 +165,7 @@ init_sunrpc(void)
 static void __exit
 cleanup_sunrpc(void)
 {
+	cleanup_socket_xprt();
 	unregister_rpc_pipefs();
 	rpc_destroy_mempool();
 	if (cache_unregister(&ip_map_cache))

net/sunrpc/xprtsock.c

@@ -1502,3 +1502,21 @@ struct rpc_xprt *xs_setup_tcp(struct sockaddr *addr, size_t addrlen, struct rpc_
 
 	return xprt;
 }
+
+/**
+ * init_socket_xprt - stub
+ *
+ */
+int init_socket_xprt(void)
+{
+	return 0;
+}
+
+/**
+ * cleanup_socket_xprt - stub
+ *
+ */
+void cleanup_socket_xprt(void)
+{
+	return;
+}