Suppress build warning.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84453 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/TypeLoc.cpp b/lib/AST/TypeLoc.cpp
index 7e6b110..50a5120 100644
--- a/lib/AST/TypeLoc.cpp
+++ b/lib/AST/TypeLoc.cpp
@@ -92,5 +92,5 @@
 void TypeLoc::initializeImpl(TypeLoc TL, SourceLocation Loc) {
   do {
     TypeLocInitializer(Loc).Visit(TL);
-  } while (TL = TL.getNextTypeLoc());
+  } while ((TL = TL.getNextTypeLoc()));
 }