Update autotest tests to use make -j where possible.

client/site_tests/firmware_VbootCrypto/firmware_VbootCrypto.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 os
 
 from autotest_lib.client.bin import test, utils
 from autotest_lib.client.common_lib import error
 
 class firmware_VbootCrypto(test.test):
     """
     Tests for correctness of verified boot reference crypto implementation.
     """
     version = 1
     preserve_srcdir = True
 
     # TODO(gauravsh): Disable this autotest until we have a way
     # of running these in a 64-bit environment (since for x86, this
     # code is run in 64-bit mode.
     #
     # This issue is tracked as Issue 3792 on the Chromium OS Bug Tracker.
     # http://code.google.com/p/chromium-os/issues/detail?id=3792
     def setup_Disabled(self):
         os.chdir(self.srcdir)
-        utils.system('make clean all')
+        utils.make('clean all')
 
 
     # Parses the [result] and output the key-value pairs.
     def __output_result_keyvals(self, results):
         for keyval in results.splitlines():
             if keyval.strip().startswith('#'):
                 continue
             key, val = keyval.split(':')
             self.keyvals[key.strip()] = float(val)
 
@@ skipping 145 matching lines @@
 
     def run_splicing(self):
         success = self.__splicing_tests()
         if not success:
             raise error.TestFail("Splicing Tests Failed")
 
 
     def run_once(self, suite='crypto'):
         self.__generate_test_cases()
         getattr(self, 'run_' + suite)()