NFSv4: fix getacl head length estimation

[ Upstream commit 6682c14b ]

Bitmap and attrlen follow immediately after the op reply header.  This
was an oversight from commit bf118a34.

Consequences of this are just minor efficiency (extra calls to
xdr_shrink_bufhead).

Fixes: bf118a34 "NFSv4: include bitmap in nfsv4 get acl data"
Reviewed-by: Kinglong Mee <kinglongmee@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

fs/nfs/nfs4xdr.c

@@ -2470,7 +2470,7 @@ static void nfs4_xdr_enc_getacl(struct rpc_rqst *req, struct xdr_stream *xdr,
 	encode_compound_hdr(xdr, req, &hdr);
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->fh, &hdr);
-	replen = hdr.replen + op_decode_hdr_maxsz + 1;
+	replen = hdr.replen + op_decode_hdr_maxsz;
 	encode_getattr_two(xdr, FATTR4_WORD0_ACL, 0, &hdr);
 
 	xdr_inline_pages(&req->rq_rcv_buf, replen << 2,