minor clean up

Author: Stephane Landelle

src/main/java/com/ning/http/client/providers/netty/ResponseBodyPart.java

@@ -60,7 +60,7 @@ public byte[] getBodyPartBytes() {
             return bytes.get();
         }
 
-        byte[] b = ChannelBufferUtil.channelBuffer2bytes(getChannelBuffer());
+        byte[] b = ChannelBufferUtil.channelBuffer2bytes(content);
         bytes.set(b);
         return b;
     }