NFSv4: Ensure that we track the NFSv4 lock state in read/write requests.

This patch fixes bugzilla entry 14501:
  https://bugzilla.kernel.org/show_bug.cgi?id=14501

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 5a33a92..87adc27 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -190,6 +190,7 @@
 	data->args.pages  = data->pagevec;
 	data->args.count  = count;
 	data->args.context = get_nfs_open_context(req->wb_context);
+	data->args.lock_context = req->wb_lock_context;
 
 	data->res.fattr   = &data->fattr;
 	data->res.count   = count;