Workarounds build failure for ghc-6.12

[18 of 27] Compiling System.Console.Haskeline.Backend.Terminfo ( System/Console/Haskeline/Backend/Terminfo.hs, dist/build/System/Console/Haskeline/Backend/Terminfo.o )

System/Console/Haskeline/Backend/Terminfo.hs:200:9:
    Inferred type is less polymorphic than expected
          Quantified type variable `m' escapes
              In the expression: Writer.tell
                  In the definition of `output': output = Writer.tell
diff --git a/System/Console/Haskeline/Backend/Terminfo.hs b/System/Console/Haskeline/Backend/Terminfo.hs
index 1bd0373..d01e9ba 100644
--- a/System/Console/Haskeline/Backend/Terminfo.hs
+++ b/System/Console/Haskeline/Backend/Terminfo.hs
@@ -197,7 +197,7 @@ runActionT m = do
     return x
 
 output :: TermAction -> ActionM ()
-output = Writer.tell
+output = \x -> Writer.tell x
 
 outputText :: String -> ActionM ()
 outputText str = posixEncode str >>= output . const . termText . B.unpack