NFSv4: nfs4_locku_done must release the sequence id

commit 2b1bc308f492589f7d49012ed24561534ea2be8c upstream.

If the state recovery machinery is triggered by the call to
nfs4_async_handle_error() then we can deadlock.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b106b97..3b005eb 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4306,6 +4306,7 @@
 			if (nfs4_async_handle_error(task, calldata->server, NULL) == -EAGAIN)
 				rpc_restart_call_prepare(task);
 	}
+	nfs_release_seqid(calldata->arg.seqid);
 }
 
 static void nfs4_locku_prepare(struct rpc_task *task, void *data)