Revert "Turn some C-style vararg into variadic templates"

This reverts commit r299699, the examples needs to be updated.

llvm-svn: 299702
diff --git a/llvm/lib/CodeGen/CountingFunctionInserter.cpp b/llvm/lib/CodeGen/CountingFunctionInserter.cpp
index 8182d43..1e46a7a 100644
--- a/llvm/lib/CodeGen/CountingFunctionInserter.cpp
+++ b/llvm/lib/CodeGen/CountingFunctionInserter.cpp
@@ -40,7 +40,8 @@
 
       Type *VoidTy = Type::getVoidTy(F.getContext());
       Constant *CountingFn =
-          F.getParent()->getOrInsertFunction(CountingFunctionName, VoidTy);
+        F.getParent()->getOrInsertFunction(CountingFunctionName,
+                                           VoidTy, nullptr);
       CallInst::Create(CountingFn, "", &*F.begin()->getFirstInsertionPt());
       return true;
     }