WINECFG: use directory harddiskvolume1 for mapping drive C

[Dan Kegel]

To state the obvious, another workaround is:
  cd ~/.wine
  mv drive_c harddiskvolume1
  cd dosdevices
  ln -sf ../harddiskvolume1 c:

BTW this is http://bugs.winehq.org/show_bug.cgi?id=5351
- Dan