Change references to 'const ProgramState *' to typedef 'ProgramStateRef'.

At this point this is largely cosmetic, but it opens the door to replace
ProgramStateRef with a smart pointer that more eagerly acts in the role
of reclaiming unused ProgramState objects.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149081 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp b/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
index b074ff9..cdf7ebc 100644
--- a/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
@@ -35,7 +35,7 @@
 
 void UndefResultChecker::checkPostStmt(const BinaryOperator *B,
                                        CheckerContext &C) const {
-  const ProgramState *state = C.getState();
+  ProgramStateRef state = C.getState();
   const LocationContext *LCtx = C.getLocationContext();
   if (state->getSVal(B, LCtx).isUndef()) {
     // Generate an error node.