Add back a condition accidentially removed in r184470.

llvm-svn: 184496
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index deb1ba1..16b12ea 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -608,7 +608,7 @@
     return false;
 
   VariadicCallType CallType;
-  if (!Proto) {
+  if (!Proto || !Proto->isVariadic()) {
     CallType = VariadicDoesNotApply;
   } else if (Ty->isBlockPointerType()) {
     CallType = VariadicBlock;