[Test] Fix typo so that SixSpeed/SpreadLiteral/Babel is actually run.

BUG=v8:5940

Change-Id: Ibf4061244fbde2fabf2a13307a8f646258c9efc6
Reviewed-on: https://chromium-review.googlesource.com/439309
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Franziska Hinkelmann <franzih@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43004}

test/js-perf-test/SixSpeed.json

@@ -119,7 +119,7 @@
         {
           "name": "Babel",
           "main": "run.js",
-          "test_flags": ["super_spread/babel"]
+          "test_flags": ["spread_literal/babel"]
         },
         {
           "name": "ES6",