send callback directly

src/topics.js

@@ -294,9 +294,7 @@ var async = require('async'),
 				topicData.locked = parseInt(topicData.locked, 10) === 1;
 				topicData.pinned = parseInt(topicData.pinned, 10) === 1;
 
-				plugins.fireHook('filter:topic.get', topicData, function(err, topicData) {
+				plugins.fireHook('filter:topic.get', topicData, callback);
-					callback(null, topicData);
-				});
 			});
 		});
 	};