examples/analyzer-plugin/: unbreak build

It was never updated for API changes in r149311/r149336/r149339
and r147688.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150202 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/examples/analyzer-plugin/MainCallChecker.cpp b/examples/analyzer-plugin/MainCallChecker.cpp
index 85f7754..34fb578 100644
--- a/examples/analyzer-plugin/MainCallChecker.cpp
+++ b/examples/analyzer-plugin/MainCallChecker.cpp
@@ -16,9 +16,10 @@
 } // end anonymous namespace
 
 void MainCallChecker::checkPreStmt(const CallExpr *CE, CheckerContext &C) const {
-  const ProgramState *state = C.getState();
+  const ProgramStateRef state = C.getState();
+  const LocationContext *LC = C.getLocationContext();
   const Expr *Callee = CE->getCallee();
-  const FunctionDecl *FD = state->getSVal(Callee).getAsFunctionDecl();
+  const FunctionDecl *FD = state->getSVal(Callee, LC).getAsFunctionDecl();
 
   if (!FD)
     return;