Clean up comment.

llvm-svn: 175411
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 28cba14..cb207ff 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -2821,7 +2821,7 @@
   }
 
 
-  // -fborland-extensions=0 is default.
+  // -fno-borland-extensions is default.
   if (Args.hasFlag(options::OPT_fborland_extensions,
                    options::OPT_fno_borland_extensions, false))
     CmdArgs.push_back("-fborland-extensions");