Fix leak in my recent fix for PR8442.

llvm-svn: 118490
diff --git a/llvm/lib/VMCore/Attributes.cpp b/llvm/lib/VMCore/Attributes.cpp
index d854628..c9240e5 100644
--- a/llvm/lib/VMCore/Attributes.cpp
+++ b/llvm/lib/VMCore/Attributes.cpp
@@ -132,7 +132,7 @@
   void DropRef() {
     sys::SmartScopedLock<true> Lock(*ALMutex);
     sys::cas_flag old = RefCount++;
-    if (old == 0)
+    if (old == 1)
       delete this;
   }