Change the return value of drain. False means the object wasn't able to drain yet.

Change the return value of drain.  False means the object wasn't able to drain yet.

src/python/m5/config.py:
    Invert the return value.
src/sim/sim_object.cc:
    Invert the return value of drain.
src/sim/sim_object.hh:
    Change the return value of drain.

--HG--
extra : convert_revision : 41bb122c6f29302d8b3815d7bd6a2ea8fba64df9