bsc: Work a bit on opening the SCCP connection to the MSC.

Most of the code is still stubs but the structure is a lot
cleaner than the one in the on-waves/bsc-master branch.
diff --git a/openbsc/src/bsc/osmo_bsc_sccp.c b/openbsc/src/bsc/osmo_bsc_sccp.c
index 694a30f..d1fff91 100644
--- a/openbsc/src/bsc/osmo_bsc_sccp.c
+++ b/openbsc/src/bsc/osmo_bsc_sccp.c
@@ -25,6 +25,7 @@
 #include <openbsc/debug.h>
 
 #include <osmocore/gsm0808.h>
+#include <osmocore/talloc.h>
 #include <osmocore/protocol/gsm_08_08.h>
 
 #include <osmocom/sccp/sccp.h>
@@ -75,13 +76,28 @@
 	return 0;
 }
 
-int bsc_create_new_connection(struct gsm_subscriber_connection *conn,
-			      struct msgb *msg, uint16_t chosen_channel)
+int bsc_create_new_connection(struct gsm_subscriber_connection *conn)
 {
 	LOGP(DMSC, LOGL_ERROR, "Not implemented yet.\n");
 	return -1;
 }
 
+int bsc_open_connection(struct gsm_subscriber_connection *conn, struct msgb *msg)
+{
+	LOGP(DMSC, LOGL_ERROR, "Not implemented yet.\n");
+	return -1;
+}
+
+int bsc_delete_connection(struct gsm_subscriber_connection *conn)
+{
+	if (!conn->sccp_con)
+		return 0;
+
+	talloc_free(conn->sccp_con);
+	conn->sccp_con = NULL;
+	return 0;
+}
+
 int osmo_bsc_sccp_init(struct gsm_network *gsmnet)
 {
 	sccp_set_log_area(DSCCP);