drop more llvm:: prefixes on OwningPtr<>

More cleanup after r149798.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150379 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/examples/analyzer-plugin/MainCallChecker.cpp b/examples/analyzer-plugin/MainCallChecker.cpp
index 34fb578..48a9795 100644
--- a/examples/analyzer-plugin/MainCallChecker.cpp
+++ b/examples/analyzer-plugin/MainCallChecker.cpp
@@ -8,7 +8,7 @@
 
 namespace {
 class MainCallChecker : public Checker < check::PreStmt<CallExpr> > {
-  mutable llvm::OwningPtr<BugType> BT;
+  mutable OwningPtr<BugType> BT;
 
 public:
   void checkPreStmt(const CallExpr *CE, CheckerContext &C) const;