nfsd4: read size estimate should include padding

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 2c1ee70..77c4369 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1489,7 +1489,7 @@
 	if (rlen > maxcount)
 		rlen = maxcount;
 
-	return (op_encode_hdr_size + 2) * sizeof(__be32) + rlen;
+	return (op_encode_hdr_size + 2 + XDR_QUADLEN(rlen)) * sizeof(__be32);
 }
 
 static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)