Revert "[test] Temporary debug output for hanging tests"

This reverts commit c45bc57d.

Reason for revert: Seen output once, that is enough.

Original change's description:
> [test] Temporary debug output for hanging tests
> 
> TBR=sigurds@chromium.org,sergiyb@chromium.org
> 
> Bug: v8:8292
> Change-Id: Ic03e2884ef645231807762f6b0210e69c5f9ac74
> Reviewed-on: https://chromium-review.googlesource.com/c/1282604
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56674}

TBR=machenbach@chromium.org,sigurds@chromium.org,sergiyb@chromium.org

Change-Id: Id5a2414682a9795998b86369368276e95c11394c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8292
Reviewed-on: https://chromium-review.googlesource.com/c/1283112Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56683}

tools/testrunner/testproc/sigproc.py

@@ -2,9 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import platform
 import signal
-import subprocess
 
 from . import base
 from testrunner.local import utils
@@ -31,8 +29,3 @@ class SignalProc(base.TestProcObserver):
     print '>>> SIGTERM received, early abort...'
     self.exit_code = utils.EXIT_CODE_TERMINATED
     self.stop()
-
-    # TODO(machenbach): Remove temporary output after investigating:
-    # https://crbug.com/v8/8292
-    if platform.system() == 'Linux':
-      subprocess.call('ps -aux | grep d8', shell=True)