Fix BootControlChromeOS unittest references.

These references were not updated in the last CL.

Bug: None
TEST=FEATURES=test emerge-link update_engine
TBR=garnold@google.com

Change-Id: I293baa3b3ccc135829a9e0bdd533befb0283fa3f
diff --git a/update_engine.gyp b/update_engine.gyp
index 2fa6ae8..b40d5b3 100644
--- a/update_engine.gyp
+++ b/update_engine.gyp
@@ -429,11 +429,11 @@
           ],
           'includes': ['../../../platform2/common-mk/common_test.gypi'],
           'sources': [
+            'boot_control_chromeos_unittest.cc',
             'chrome_browser_proxy_resolver_unittest.cc',
             'common/action_pipe_unittest.cc',
             'common/action_processor_unittest.cc',
             'common/action_unittest.cc',
-            'common/boot_control_chromeos_unittest.cc',
             'common/certificate_checker_unittest.cc',
             'common/fake_prefs.cc',
             'common/hash_calculator_unittest.cc',