xdr_callhdr
extern bool_t xdr_callhdr (XDR *, struct rpc_msg *);
if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
if (! xdr_callhdr(xdrs, &call_msg))
if (! xdr_callhdr(&(ct->ct_xdrs), &call_msg)) {
__weak_alias(xdr_callhdr,_xdr_callhdr)
if (!xdr_callhdr(&outxdr, &call_msg)) {