atrf-xtal/atben.c: restructured the code for better clarity; added warnings
atrf-xtal/atben.c: restructured the code for better clarity; added warnings

cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan