NFSv4: Cache the NFSv4/v4.1 client owner_id in the struct nfs_client

Ensure that we cache the NFSv4/v4.1 client owner_id so that we can
verify it when we're doing trunking detection.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index d949d0f..6ee9bf6 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -228,6 +228,7 @@
 	kfree(clp->cl_serverowner);
 	kfree(clp->cl_serverscope);
 	kfree(clp->cl_implid);
+	kfree(clp->cl_owner_id);
 }
 
 void nfs4_free_client(struct nfs_client *clp)