Fix authutil call

scripts/slave/recipes/infra/recipe_roll_tryjob.expected/bad_patches.json

 [
   {
     "cmd": [
-      "authutil",
+      "/opt/infra-tools/authutil",
       "token"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "Get auth token",
     "stdout": "/path/to/tmp/"
   },
   {
     "cmd": [
       "python",
       "-u",
       "import sys; sys.exit(1)"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "Invalid patchset list",
     "~followup_annotations": [
       "step returned non-zero exit code: 1",
       "@@@STEP_TEXT@You have two patches for 'build'. Patches seen so far: {'build': RietveldPatch(project='build', server='https://f.e.w', issue='1', patchset='1')}@@@",
       "@@@STEP_FAILURE@@@"
     ]
   },
   {
     "name": "$result",
     "reason": "Step('Invalid patchset list') failed with return_code 1",
     "status_code": 1
   }
 ]