[PLG_COURSES_DISCUSSIONS] Fixed misnamed var
[PLG_COURSES_DISCUSSIONS] Fixed misnamed var

anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,anthonyfuentes/hubzero-cms,zooley/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms,anthonyfuentes/hubzero-cms