c-index-test: Pass appropriate client data.

llvm-svn: 96317
diff --git a/clang/tools/c-index-test/c-index-test.c b/clang/tools/c-index-test/c-index-test.c
index 543e444..d4771c7 100644
--- a/clang/tools/c-index-test/c-index-test.c
+++ b/clang/tools/c-index-test/c-index-test.c
@@ -41,7 +41,7 @@
 static unsigned CreateTranslationUnit(CXIndex Idx, const char *file,
                                       CXTranslationUnit *TU) {
   
-  *TU = clang_createTranslationUnit(Idx, file, PrintDiagnosticCallback, 0);
+  *TU = clang_createTranslationUnit(Idx, file, PrintDiagnosticCallback, stderr);
   if (!TU) {
     fprintf(stderr, "Unable to load translation unit from '%s'!\n", file);
     return 0;