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/cc1as_main.cpp b/tools/driver/cc1as_main.cpp
index fc8c5dc..cc4400a 100644
--- a/tools/driver/cc1as_main.cpp
+++ b/tools/driver/cc1as_main.cpp
@@ -411,7 +411,7 @@
 
   // Honor -help.
   if (Asm.ShowHelp) {
-    llvm::OwningPtr<driver::OptTable> Opts(driver::createCC1AsOptTable());
+    OwningPtr<driver::OptTable> Opts(driver::createCC1AsOptTable());
     Opts->PrintHelp(llvm::outs(), "clang -cc1as", "Clang Integrated Assembler");
     return 0;
   }