SUNRPC: cleanup rpc credential cache garbage collection

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c
index 6c905fb..537d0e8 100644
--- a/net/sunrpc/auth_null.c
+++ b/net/sunrpc/auth_null.c
@@ -133,6 +133,7 @@
 
 static
 struct rpc_cred null_cred = {
+	.cr_lru		= LIST_HEAD_INIT(null_cred.cr_lru),
 	.cr_auth	= &null_auth,
 	.cr_ops		= &null_credops,
 	.cr_count	= ATOMIC_INIT(1),