MC: Change object writers to use endian::Writer. NFCI.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47040

llvm-svn: 332861
diff --git a/llvm/lib/MC/MCLinkerOptimizationHint.cpp b/llvm/lib/MC/MCLinkerOptimizationHint.cpp
index 97f9541..2f85814 100644
--- a/llvm/lib/MC/MCLinkerOptimizationHint.cpp
+++ b/llvm/lib/MC/MCLinkerOptimizationHint.cpp
@@ -36,7 +36,7 @@
 
 void MCLOHDirective::emit(MachObjectWriter &ObjWriter,
                           const MCAsmLayout &Layout) const {
-  raw_ostream &OutStream = ObjWriter.getStream();
+  raw_ostream &OutStream = ObjWriter.W.OS;
   emit_impl(OutStream, ObjWriter, Layout);
 }