Fix an obvious type. Patch by Ivan Krasin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136900 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp
index 91233d6..6b5dfc2 100644
--- a/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/lib/Transforms/Scalar/ObjCARC.cpp
@@ -1316,7 +1316,7 @@
     }
 
     void clearBottomUpPointers() {
-      PerPtrTopDown.clear();
+      PerPtrBottomUp.clear();
     }
 
     void clearTopDownPointers() {