Fix eslint rules (#5117)

* Fix semi linter rule

* Fix semi-spacing linter rule

* Fix no-undef-init linter rule

* Fix space-before-blocks linter rule

src/topics.js

@@ -393,7 +393,7 @@ var social = require('./social');
 					});
 				}, next);
 			}
-		], function (err){
+		], function (err) {
 			callback(err);
 		});
 	};