[Javascript] Remove newly introduced trailing whitespace in flatbuffer.js (#5300)

* Remove newly introduced trailing whitespace in flatbuffer.js

The newly introduced clear function has some trailing white space in an
otherwise whitespace clean file. Remove it.

* Remove spurious new line in the BytesBuffer construction

Another spurious white space introduced by the clear() PR.

js/flatbuffers.js

@@ -829,7 +829,6 @@ flatbuffers.ByteBuffer = function(bytes) {
    * @private
    */
   this.position_ = 0;
-
 };
 
 /**