[analyzer] When a symbol is null, we should track its constraints.

Because of this, we would previously emit NO path notes when a parameter
is constrained to null (because there are no stores). Now we show where we
made the assumption, which is much more useful.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161280 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
index 6937374..483082a 100644
--- a/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -252,8 +252,7 @@
     BugReport *report = new BugReport(*BT, os.str(), N);
 
     report->addRange(S->getSourceRange());
-    report->addVisitor(bugreporter::getTrackNullOrUndefValueVisitor(N, S,
-                                                                    report));
+    bugreporter::addTrackNullOrUndefValueVisitor(N, S, report);
     C.EmitReport(report);
     return NULL;
   }