[Statistics] Use the new Statistic::updateMax to atomically calculate a maximum value statistic.

llvm-svn: 303320
diff --git a/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp b/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
index 0fe0f3a..c47edc7 100644
--- a/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
+++ b/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
@@ -674,10 +674,8 @@
 
   DisplayFunction(D, Mode, IMode);
   CFG *DeclCFG = Mgr->getCFG(D);
-  if (DeclCFG) {
-    unsigned CFGSize = DeclCFG->size();
-    MaxCFGSize = MaxCFGSize < CFGSize ? CFGSize : MaxCFGSize;
-  }
+  if (DeclCFG)
+    MaxCFGSize.updateMax(DeclCFG->size());
 
   BugReporter BR(*Mgr);