buffer: minor cleanup from rebase

PR-URL: https://github.com/nodejs/io.js/pull/2003
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>

lib/internal/buffer_new.js

@@ -457,16 +457,7 @@ Buffer.prototype.write = function(string, offset, length, encoding) {
 
   // XXX legacy write(string, encoding, offset, length) - remove in v0.13
   } else {
-    if (!writeWarned) {
-      if (process.throwDeprecation)
-        throw new Error(writeMsg);
-      else if (process.traceDeprecation)
-        console.trace(writeMsg);
-      else
-        console.error(writeMsg);
-      writeWarned = true;
-    }
-
+    writeWarned = internalUtil.printDeprecationMessage(writeMsg, writeWarned);
     var swap = encoding;
     encoding = offset;
     offset = length >>> 0;