Fixed bug in GREndPathNodeBuilder: only return a node if it wasn't in the node cache.

llvm-svn: 49907
diff --git a/clang/lib/Analysis/GRCoreEngine.cpp b/clang/lib/Analysis/GRCoreEngine.cpp
index ffb2fd2..7ad7f73 100644
--- a/clang/lib/Analysis/GRCoreEngine.cpp
+++ b/clang/lib/Analysis/GRCoreEngine.cpp
@@ -456,7 +456,8 @@
   if (IsNew) {
     Node->markAsSink();
     Eng.G->addEndOfPath(Node);
+    return Node;
   }
   
-  return Node;
+  return NULL;
 }