Revert "Try to update the test to fix the breakage With the new warning, we are showi...

Revert "Try to update the test to fix the breakage With the new warning, we are showing one more output in the test."

This reverts commit r349064.

This wasn't updating the right test.  Causing (not the different line number
from the previous revert):

======================================================================
FAIL: test_diagnostic_warning (tests.cindex.test_diagnostics.TestDiagnostics)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/buildslave/jenkins/workspace/clang-stage1-configure-RA/llvm/tools/clang/bindings/python/tests/cindex/test_diagnostics.py", line 18, in test_diagnostic_warning
    self.assertEqual(len(tu.diagnostics), 2)
AssertionError: 1 != 2

llvm-svn: 349118