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/SafeStack.cpp b/llvm/lib/CodeGen/SafeStack.cpp
index e6981e8..2b82df2 100644
--- a/llvm/lib/CodeGen/SafeStack.cpp
+++ b/llvm/lib/CodeGen/SafeStack.cpp
@@ -450,8 +450,8 @@
                                 /* Unreachable */ true, Weights);
   IRBuilder<> IRBFail(CheckTerm);
   // FIXME: respect -fsanitize-trap / -ftrap-function here?
-  Constant *StackChkFail =
-      F.getParent()->getOrInsertFunction("__stack_chk_fail", IRB.getVoidTy());
+  Constant *StackChkFail = F.getParent()->getOrInsertFunction(
+      "__stack_chk_fail", IRB.getVoidTy(), nullptr);
   IRBFail.CreateCall(StackChkFail, {});
 }