LCLS: use libosmocore function to add status

* use gsm0808_create_ass_compl2() to add BSS Status IE to Assignment
  Complete message
* drop local helpers

Depends-on: (libosmocore) I547c6b8707123aa8c1ef636db88908df112d90a4
Change-Id: I6916928391667cd9c345becf00e7c8561846c295
Related: OS#2487
3 files changed