src: remove duplicate byteLength from Buffer

Commit 36a7795 introduced a duplicate Buffer byteLength property.

PR-URL: #1438
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>

Author: JacksonTian

src/node_buffer.cc

@@ -745,7 +745,6 @@ void Initialize(Handle<Object> target,
 
   env->SetMethod(target, "setupBufferJS", SetupBufferJS);
 
-  env->SetMethod(target, "byteLength", ByteLength);
   env->SetMethod(target, "byteLength", ByteLength);
   env->SetMethod(target, "compare", Compare);
   env->SetMethod(target, "fill", Fill);