[Node] Removing incorrect typing for `buffer.INSPECT_MAX_BYTES`.

From http://nodejs.org/api/buffer.html#buffer_buffer_inspect_max_bytes:

"...this is a property on the buffer module returned by require('buffer'), not on the Buffer global, or a buffer instance."

The Node typings do not have a notion of a buffer module, and introducing one would be more work than might be useful. It contains a reference to `Buffer` and `SlowBuffer`, which are currently defined as variables in the typings. I believe I would need
 to redefine these in the module definition.

If anyone has any ideas for how to efficiently restructure this, let me know.