[Test] Fix the regex in array JSPerfTest.

The regex was slightly off, meaning the results would not
display properly.

Change-Id: Ie3b2bf54a50bffde9b64663d7b8b8c0ad39a1212
Reviewed-on: https://chromium-review.googlesource.com/458416Reviewed-by: Franziska Hinkelmann <franzih@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44007}

test/js-perf-test/JSTests.json

@@ -347,7 +347,7 @@
       "resources": [
         "filter.js"
       ],
-      "results_regexp": "^Array\\-%s\\(Scope\\): (.+)$",
+      "results_regexp": "^%s\\-Array\\(Score\\): (.+)$",
       "tests": [
         {"name": "Filter"}
       ]