libmsc/gsm_04_80.c: use gsm0480_create_release_complete()

The previous implementation of msc_send_ussd_release_complete() was
based on gsm0480_create_ussd_release_complete(), that doesn't
allow to specify GSM 04.07 transaction identifier.

The ability to specify particular transaction identifier
is required for handling multiple SS/USSD transactions.

Change-Id: Id2975c3383f18e83124ba38927c03980d67ddadb
Depends Change-Id: (libosmocore) Ie3ac85fcef90a5e532334ba3482804d5305c88d7
3 files changed