fix Windows

Author: kazu-yamamoto

Network/Socket/Internal.hs

@@ -93,11 +93,11 @@ annotateIOException io anno = modifyIOError f io
            Just n -> "[" ++ showErrno n ++ "] "
 
 showErrno :: CInt -> String
-showErrno n = case lookup (Errno n) errnoNames of
+showErrno n = case lookup (C.Errno n) errnoNames of
   Nothing -> show n
   Just name -> name
 
-errnoNames :: [(Errno, String)]
+errnoNames :: [(C.Errno, String)]
 errnoNames = [
     (C.eACCES,          "EACCES")
   , (C.eADDRINUSE,      "EADDRINUSE")