Bug 1702568 - Fixes eslint errors in browser/extensions/screenshots/randomString.js. r=emalysz

Differential Revision: https://phabricator.services.mozilla.com/D110749

browser/extensions/screenshots/randomString.js

@@ -7,7 +7,8 @@
 "use strict";
 
 this.randomString = function randomString(length, chars) {
-  const randomStringChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+  const randomStringChars =
+    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
   chars = chars || randomStringChars;
   let result = "";
   for (let i = 0; i < length; i++) {