c/s 2d2f789 "tools: rename libxc's evtchn_port_or_error_t with an xc_
prefix" doesn't cater for older applications which have requested
XC_WANT_COMPAT_EVTCHN_API
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>