Remove the extra done in gr-reporting_test

Change-Id: Id87f1bff9839dd4aabb4f33781f580235ed22487
(cherry picked from commit 6c2b0b0a44ff26264fe6b842762812839b719acb)

polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html

diff --git a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html
index ec24b19..c357979 100644
--- a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html
+++ b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html
@@ -191,7 +191,6 @@
       assert.isTrue(element.reporter.calledOnce);
       assert.throws(() => {
         timer.end();
-        done();
       }, 'Timer for "foo-bar" already ended.');
     });