[C++11] Use 'nullptr'. StaticAnalyzer edition.

llvm-svn: 209642
diff --git a/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
index 9b5c852..f8f5cf9 100644
--- a/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
@@ -61,7 +61,7 @@
 public:
   WalkAST(const CheckerBase *checker, BugReporter &br,
           AnalysisDeclContext *ac)
-      : Checker(checker), BR(br), AC(ac), visitingCallExpr(0) {}
+      : Checker(checker), BR(br), AC(ac), visitingCallExpr(nullptr) {}
 
   bool hasWork() const { return !WList.empty(); }