remove max_length calculation in orca estimators (#4189)
remove max_length calculation in orca estimators (#4189)

* remove max_length

* fix style
yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL