eliminate compiler warnings in Bscan.bsv
eliminate compiler warnings in Bscan.bsv

Change-Id: Id1da608735a8be8e7cb9b05b34ac95523be95a87

csail-csg/connectal,csail-csg/connectal,hanw/connectal,chenm001/connectal,8l/connectal,chenm001/connectal,chenm001/connectal,csail-csg/connectal,cambridgehackers/connectal,hanw/connectal,8l/connectal,chenm001/connectal,cambridgehackers/connectal,hanw/connectal,cambridgehackers/connectal,hanw/connectal,8l/connectal,8l/connectal,chenm001/connectal,hanw/connectal,csail-csg/connectal,cambridgehackers/connectal,8l/connectal,cambridgehackers/connectal,csail-csg/connectal