Update autotest tests to use make -j where possible.

client/site_tests/hardware_TPMFirmware/hardware_TPMFirmware.py

 # 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.
 
 import logging, os, re, sys, shutil
 from autotest_lib.client.bin import test, utils
 
 class hardware_TPMFirmware(test.test):
     """
     Test of TPM functionality needed in firmware (client side of the test).
     See also server/site_tests/hardware_TPMFirmwareServer.
     """
     version = 1
     preserve_srcdir = True
 
     # Cross-compiles TLCL test suite and other needed code.
     # TODO(semenzato): tpm_takeownership is currently available by making
     # tpm-tools an RDEPEND in the autotest ebuild.  See that file for a
     # better way.
     def setup(self):
         sysroot = os.environ['SYSROOT']
         bin_path = os.path.join(sysroot, 'usr/sbin/tpm_takeownership')
         shutil.copy(bin_path, self.bindir)
-        utils.system('make -C %s' % self.srcdir)
+        utils.make('-C %s' % self.srcdir)
 
 
     # Runs a command, logs the output, and returns the exit status.
     def tpm_run(self, cmd, ignore_status=False):
         output = utils.run(cmd, ignore_status=ignore_status)
         logging.info(output)
         self.job.set_state("client_status", output.exit_status)
 
 
     # Sets up the system (if it isn't already) to run the tpm binaries.  This
@@ skipping 17 matching lines @@
             self.tpm_setup()
             self.tpm_write_status(0)
         elif (subtest == 'takeownership'):
             self.tpm_setup(with_tcsd=True)
             own_cmd = os.path.join(self.bindir, "tpm_takeownership -y -z")
             self.tpm_run(own_cmd)
         else:
             self.tpm_setup()
             cmd = os.path.join(self.srcdir, subtest)
             self.tpm_run(cmd, ignore_status=True)