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/tools/driver/cc1_main.cpp b/tools/driver/cc1_main.cpp
index ad3f350..e491d61 100644
--- a/tools/driver/cc1_main.cpp
+++ b/tools/driver/cc1_main.cpp
@@ -117,7 +117,7 @@
 
 int cc1_main(const char **ArgBegin, const char **ArgEnd,
              const char *Argv0, void *MainAddr) {
-  llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());
+  OwningPtr<CompilerInstance> Clang(new CompilerInstance());
   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
 
   // Run clang -cc1 test.