update ants_build_path refs in register_scans.m
update ants_build_path refs in register_scans.m

aditiiyer/CERR,cerr/CERR,cerr/CERR,cerr/CERR,cerr/CERR,aditiiyer/CERR,cerr/CERR,aditiiyer/CERR,cerr/CERR,cerr/CERR,aditiiyer/CERR,cerr/CERR,cerr/CERR,aditiiyer/CERR,aditiiyer/CERR,aditiiyer/CERR,aditiiyer/CERR