drop msc_compl_l3() return value

msc_compl_l3() always returns MSC_CONN_ACCEPT, because the conn FSM handles (or
should handle) all reject cases. The accept/reject return value is a legacy
from libbsc internally passing a conn over to libmsc, in osmo-nitb.

Drop enum msc_compl_l3_rc.
Change msc_compl_l3_rc() to return void.
Change all callers to always act like for acceptance, as they always did anyway.
Drop some local variables now no longer needed.
Adjust the comment to msc_compl_l3().
Drop a bunch of #if-0'd code from msc_compl_l3().

Change-Id: I759d15f4e820d5fc16397ed7210ce92308e52a09
4 files changed