NFS: move rw_mode to nfs_pageio_header

Let's try to have it in a cacheline in nfs4_proc_pgio_rpc_prepare().

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index dda19a3..4e52ac7 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4610,7 +4610,7 @@ static int nfs4_proc_pgio_rpc_prepare(struct rpc_task *task,
 		return 0;
 	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 				hdr->args.lock_context,
-				hdr->rw_ops->rw_mode) == -EIO)
+				hdr->rw_mode) == -EIO)
 		return -EIO;
 	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags)))
 		return -EIO;