BUG(2297): Fix wrong function call in XMMSSync.
BUG(2297): Fix wrong function call in XMMSSync.

It used to raise a TypeError exception when calling the missing
XMMSResult.get_error() function. It now uses XMMSResult.value() and
raises the expected XMMSError exception.

xmms2/xmms2-stable,oneman/xmms2-oneman-old,theefer/xmms2,theeternalsw0rd/xmms2,dreamerc/xmms2,oneman/xmms2-oneman-old,mantaraya36/xmms2-mantaraya36,oneman/xmms2-oneman-old,krad-radio/xmms2-krad,mantaraya36/xmms2-mantaraya36,mantaraya36/xmms2-mantaraya36,theefer/xmms2,theeternalsw0rd/xmms2,krad-radio/xmms2-krad,chrippa/xmms2,xmms2/xmms2-stable,chrippa/xmms2,krad-radio/xmms2-krad,mantaraya36/xmms2-mantaraya36,theeternalsw0rd/xmms2,six600110/xmms2,oneman/xmms2-oneman,theefer/xmms2,oneman/xmms2-oneman,oneman/xmms2-oneman,chrippa/xmms2,theeternalsw0rd/xmms2,dreamerc/xmms2,theefer/xmms2,xmms2/xmms2-stable,mantaraya36/xmms2-mantaraya36,theeternalsw0rd/xmms2,mantaraya36/xmms2-mantaraya36,theefer/xmms2,xmms2/xmms2-stable,krad-radio/xmms2-krad,six600110/xmms2,chrippa/xmms2,six600110/xmms2,theeternalsw0rd/xmms2,xmms2/xmms2-stable,xmms2/xmms2-stable,dreamerc/xmms2,krad-radio/xmms2-krad,oneman/xmms2-oneman,oneman/xmms2-oneman-old,dreamerc/xmms2,chrippa/xmms2,oneman/xmms2-oneman,dreamerc/xmms2,krad-radio/xmms2-krad,chrippa/xmms2,theefer/xmms2,six600110/xmms2,mantaraya36/xmms2-mantaraya36,six600110/xmms2,oneman/xmms2-oneman,theefer/xmms2,six600110/xmms2,oneman/xmms2-oneman-old,oneman/xmms2-oneman