sunrpc: exit_net cleanup check added

Be sure that all_clients list initialized in net_init hook was return
to initial state.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/sunrpc_syms.c

@@ -65,10 +65,13 @@ err_proc:
 
 static __net_exit void sunrpc_exit_net(struct net *net)
 {
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
 	rpc_pipefs_exit_net(net);
 	unix_gid_cache_destroy(net);
 	ip_map_cache_destroy(net);
 	rpc_proc_exit(net);
+	WARN_ON_ONCE(!list_empty(&sn->all_clients));
 }
 
 static struct pernet_operations sunrpc_net_ops = {