[js-perf-test] fixup error in JSTests.json

test/js-perf-test/JSTests.json

 {
   "name": "JSTests",
   "run_count": 5,
   "run_count_android_arm": 3,
   "run_count_android_arm64": 3,
   "timeout": 120,
   "units": "score",
   "total": true,
   "resources": ["base.js"],
   "tests": [
@@ skipping 90 matching lines @@
       "results_regexp": "^%s\\-Templates\\(Score\\): (.+)$",
       "total": true,
       "tests": [
         {"name": "Untagged"},
         {"name": "LargeUntagged"},
         {"name": "Tagged"}
       ]
     },
     {
       "name": "Object",
-      "path": ["."],
+      "path": ["Object"],
       "main": "run.js",
       "flags": ["--harmony"],
       "resources": [
         "assign.js",
         "values.js",
         "entries.js"
       ],
       "results_regexp": "^%s\\-Object\\(Score\\): (.+)$",
       "tests": [
         {"name": "Assign"},
@@ skipping 37 matching lines @@
         {"name": "for-in"},
         {"name": "for-in hasOwnProperty()"},
         {"name": "for (i < Object.keys().length)"},
         {"name": "Object.keys().forEach()"},
         {"name": "for (i < array.length)"},
         {"name": "for (i < length)"}
       ]
     }
   ]
 }