* dbus/dbus-spawn.c: (read_data),
(_dbus_babysitter_get_child_exit_status):
* dbus/dbus-spawn.h:
Add a function so we can get access to the exit status of the launch
helper.
By providing the return code and not the error we can leave the
'what does this mean?' to the bus launch code and not include it in the
dbus directory.