AU: Remove obsolete postinst --postcommit call.

BUG=6251
TEST=unit test, tested update on device

Change-Id: Ib44b4698cab5fa1f2d0b5afd04dca500c8dbe84c

Review URL: http://codereview.chromium.org/4679003
diff --git a/postinstall_runner_action.cc b/postinstall_runner_action.cc
index 21d7231..9a84563 100644
--- a/postinstall_runner_action.cc
+++ b/postinstall_runner_action.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -58,7 +58,6 @@
     vector<string> command;
     command.push_back(temp_dir + kPostinstallScript);
     command.push_back(install_device);
-    command.push_back(precommit_ ? "" : "--postcommit");
     rc = 0;
     TEST_AND_RETURN(Subprocess::SynchronousExec(command, &rc));
     bool success = (rc == 0);