CA-147800: VMStart/TC8561: Guest did not start/resume where expected.

CA-146698(https://github.com/xapi-project/xen-api/pull/1961) is not a
complete fix, xapi_vm_helpers.ml#695 pattern matching also should be
changed. Some XenRT case was broken, so revert its code changes.

Signed-off-by: Phus Lu <phus.lu@citrix.com>