NFSD: Replace READ* macros in nfsd4_decode_open_confirm()

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4xdr.c

@@ -1155,18 +1155,18 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
 static __be32
 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
 {
-	DECODE_HEAD;
+	__be32 status;
 
 	if (argp->minorversion >= 1)
 		return nfserr_notsupp;
 
-	status = nfsd4_decode_stateid(argp, &open_conf->oc_req_stateid);
+	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
 	if (status)
 		return status;
-	READ_BUF(4);
-	open_conf->oc_seqid = be32_to_cpup(p++);
+	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
+		return nfserr_bad_xdr;
 
-	DECODE_TAIL;
+	return nfs_ok;
 }
 
 static __be32