In OutputGeomtry constructor, call update()

This avoids duplicate code for updating the HAPI_GeoInfo.
Add some macros for error checking
Make sure OutputGeometry::myParts is initialized even when HAPI_GetGeoInfo() failed

Even when HAPI_GetGeoInfo() failed, there's always at least one part. So
we want the below code to initialize myParts.
Merge branch 'cklosters/Houdini13.0-fix_geo_info' into cklosters/Houdini13.0