Make r145697 actually work.

Use the canonical type of the typedef to compare with the underlying type.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145702 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/PrintfFormatString.cpp b/lib/Analysis/PrintfFormatString.cpp
index b37b23f..e3d7650 100644
--- a/lib/Analysis/PrintfFormatString.cpp
+++ b/lib/Analysis/PrintfFormatString.cpp
@@ -290,7 +290,7 @@
 
   if (TypedefDecl *TD = dyn_cast_or_null<TypedefDecl>(D)) {
     QualType TypedefType = Ctx.getTypedefType(TD, QualType());
-    if (TD->getUnderlyingType() == Underlying)
+    if (Ctx.getCanonicalType(TypedefType) == Underlying)
       return TypedefType;
   }