Consilidate SmallPtrSet count() followed by insert() into a single insert().

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162330 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Core/RegionStore.cpp b/lib/StaticAnalyzer/Core/RegionStore.cpp
index bc4e4bb..e34f418 100644
--- a/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -477,12 +477,8 @@
   }
 
   bool AddToWorkList(const MemRegion *R, const ClusterBindings *C) {
-    if (C) {
-      if (Visited.count(C))
-        return false;
-      Visited.insert(C);
-    }
-
+    if (C && !Visited.insert(C))
+      return false;
     WL.push_back(R);
     return true;
   }