Re-enable the max-len ESLint rule. (#5265)

packages/babel-generator/src/printer.js

@@ -1,5 +1,3 @@
-/* eslint max-len: 0 */
-
 import find from "lodash/find";
 import findLast from "lodash/findLast";
 import isInteger from "lodash/isInteger";
@@ -321,6 +319,7 @@ export default class Printer {
 
     const printMethod = this[node.type];
     if (!printMethod) {
+      // eslint-disable-next-line max-len
       throw new ReferenceError(`unknown node of type ${JSON.stringify(node.type)} with constructor ${JSON.stringify(node && node.constructor.name)}`);
     }