Follow-up to r1081491: Fix broken --log-to-stdout with C tests.
Follow-up to r1081491: Fix broken --log-to-stdout with C tests.

* build/run_tests.py
  (TestHarness._run_c_test): There is no log when using
   --log-to-stdout, so don't try to write to it.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1095742 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion