Switch this to new API.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102280 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/FixItRewriter.cpp b/lib/Frontend/FixItRewriter.cpp
index cb2b44a..7c9a566 100644
--- a/lib/Frontend/FixItRewriter.cpp
+++ b/lib/Frontend/FixItRewriter.cpp
@@ -68,7 +68,7 @@
       continue;
     }
     RewriteBuffer &RewriteBuf = I->second;
-    OS << std::string(RewriteBuf.begin(), RewriteBuf.end());
+    RewriteBuf.write(OS);
     OS.flush();
   }