nfs42: decode_layoutstats does not need res parameter

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs42xdr.c

@@ -238,8 +238,7 @@ out_overflow:
 	return -EIO;
 }
 
-static int decode_layoutstats(struct xdr_stream *xdr,
-			      struct nfs42_layoutstat_res *res)
+static int decode_layoutstats(struct xdr_stream *xdr)
 {
 	return decode_op_hdr(xdr, OP_LAYOUTSTATS);
 }
@@ -343,7 +342,7 @@ static int nfs4_xdr_dec_layoutstats(struct rpc_rqst *rqstp,
 		goto out;
 	WARN_ON(res->num_dev > PNFS_LAYOUTSTATS_MAXDEV);
 	for (i = 0; i < res->num_dev; i++) {
-		status = decode_layoutstats(xdr, res);
+		status = decode_layoutstats(xdr);
 		if (status)
 			goto out;
 	}