[analyzer] bugreporter::getDerefExpr now takes a Stmt, not an ExplodedNode.

This allows it to be used in places where the interesting statement
doesn't match up with the current node. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173546 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/DereferenceChecker.cpp b/lib/StaticAnalyzer/Checkers/DereferenceChecker.cpp
index df2fd71..c77e2e3 100644
--- a/lib/StaticAnalyzer/Checkers/DereferenceChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/DereferenceChecker.cpp
@@ -157,7 +157,7 @@
                   buf.empty() ? BT_null->getDescription() : buf.str(),
                   N);
 
-  bugreporter::trackNullOrUndefValue(N, bugreporter::GetDerefExpr(N), *report);
+  bugreporter::trackNullOrUndefValue(N, bugreporter::getDerefExpr(S), *report);
 
   for (SmallVectorImpl<SourceRange>::iterator
        I = Ranges.begin(), E = Ranges.end(); I!=E; ++I)
@@ -176,7 +176,7 @@
 
       BugReport *report =
         new BugReport(*BT_undef, BT_undef->getDescription(), N);
-      bugreporter::trackNullOrUndefValue(N, bugreporter::GetDerefExpr(N),
+      bugreporter::trackNullOrUndefValue(N, bugreporter::getDerefExpr(S),
                                          *report);
       C.emitReport(report);
     }