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>