fixed compilation with icc: avoid MonetDB5/src/optimizer/opt_prelude.mx(623): error #592: variable "ret" is used before its value is set   (void) ret;          ^ by removing unnecessary "(void) ret;"
fixed compilation with icc:
avoid
MonetDB5/src/optimizer/opt_prelude.mx(623): error #592: variable "ret" is used before its value is set
  (void) ret;
         ^
by removing unnecessary "(void) ret;"

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb