use libosmocore's gsm0808_permitted_speech(), gsm0808_chosen_channel()

The guts of bssap_speech_from_lchan() and lchan_to_chosen_channel() have been
moved to libosmocore; call those instead.

The return value of bssap_speech_from_lchan() used to be -1 on error, now the
error value is 0. The only caller did not handle -1 properly, but fed it
directly to a uint8_t.

On gsm0808_chosen_channel() error, log the error. Proper handling is missing.

Fixing the error handling in send_ass_compl() is a separate issue: currently it
is limited to logging, there is no way to return an error yet, nor any actions
to take on error.

Depends: Icca23940791f97fa64dbc3f2734270b99f9550c1 (libosmocore)
Change-Id: Ib5c940a9dae11c5e26d4b47fa9d95fef889ad2f6
1 file changed