compl l3: allocate conn in gsm_08_08.c, not gsm_04_08_rr.c

Move conn allocation to bsc_compl_l3(), from gsm0408_rcvmsg().

Drop dispatch of GSCON_EV_A_DISC_IND, because a) we did not receive such
DISC.IND, and b) the lchan release will discard the conn in the regular
fashion.

In upcoming LCS patch, bsc_compl_l3() will decide whether to allocate a new
conn or whether a conn from a Perform Location Request already exists for the
subscriber.

In this patch, it becomes clear that the conn->bsub is always NULL in
bsc_compl_l3(), and that the 'log_set_context(LOG_CTX_BSC_SUBSCR, conn->bsub);'
never has the intended effect. An upcoming patch will change that.

Change-Id: I92af0f0d54c4282d782f2b29d524a64006c3b674
diff --git a/tests/handover/handover_test.c b/tests/handover/handover_test.c
index 78e8daf..ba0ec21 100644
--- a/tests/handover/handover_test.c
+++ b/tests/handover/handover_test.c
@@ -1796,7 +1796,7 @@
 int osmo_bsc_sigtran_open_conn(struct gsm_subscriber_connection *conn, struct msgb *msg) { return 0; }
 void bsc_sapi_n_reject(struct gsm_subscriber_connection *conn, uint8_t dlci, enum gsm0808_cause cause) {}
 void bsc_cipher_mode_compl(struct gsm_subscriber_connection *conn, struct msgb *msg, uint8_t chosen_encr) {}
-int bsc_compl_l3(struct gsm_subscriber_connection *conn, struct msgb *msg, uint16_t chosen_channel)
+int bsc_compl_l3(struct gsm_lchan *lchan, struct msgb *msg, uint16_t chosen_channel)
 { return 0; }
 void bsc_dtap(struct gsm_subscriber_connection *conn, uint8_t link_id, struct msgb *msg) {}
 void bsc_assign_compl(struct gsm_subscriber_connection *conn, uint8_t rr_cause) {}