erp5_officejs: fix jslint errors

5 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

01:12:09

passed ERP5.PerformanceTest-Master

00:23:06

failed ERP5.UnitTest-Master.Medusa

02:12:27

passed SlapOS.Eggs.UnitTest-Master.Python2

00:14:08

passed SlapOS.Eggs.UnitTest-Master.Python3

00:12:30