[DynInst_API:] commit: dataflowAPI: use boost::bind() instead of bind<void>()

[Josh Stone <jistone@xxxxxxxxxx>]

With boost 1.58, the boost::bind<void>() in Slicer::getPredecessors()
gave an "error: call of overloaded 'bind[...]' is ambiguous".

Every other bind in dyninst uses plain boost::bind(), which does its own
inspection of return type.  That works well in this case too, even with
older boost versions.


For full context of the error, see the build.log here:
http://koji.fedoraproject.org/koji/taskinfo?taskID=10453531