[PATCH 1 of 2 V2] bufferedinputpipe: remove an outdate comment

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1435342839 25200
#      Fri Jun 26 11:20:39 2015 -0700
# Node ID 995f1afb89fac10d4759d6c3524693ecb926b9f4
# Parent  6368c51cfad6dc5f9c46369ed5e17cf8bd09efae
bufferedinputpipe: remove an outdate comment

This comment is the remains of a intermediate implementation using

  self._buffer += data

This implementation never made it to the repository and we can safely drop the
comment.

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -325,11 +325,10 @@ class bufferedinputpipe(object):
         """read data to the buffer"""
         data = os.read(self._input.fileno(), _chunksize)
         if not data:
             self._eof = True
         else:
-            # inefficient add
             self._buffer.append(data)
 
 def popen2(cmd, env=None, newlines=False):
     # Setting bufsize to -1 lets the system decide the buffer size.
     # The default for bufsize is 0, meaning unbuffered. This leads to