Use printf() instead of wxPrintf() in cppunit details listener.

Use printf() instead of wxPrintf() in cppunit details listener.

Wide char output from wxPrintf() didn't appear at all under Linux because
stdout was switched into narrow stream mode by GNU libc due to initial use of
cout in the test.

Use printf() instead of wxPrintf() as we are only printing ASCII strings
anyhow. Of course, this is not a real fix but at least we can see the tests
results like this.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71633 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775