bsc: Point back from struct osmo_msc_data to struct gsm_network

openbsc/include/openbsc/osmo_msc_data.h

@@ -36,6 +36,9 @@ struct gsm_audio_support {
 };
 
 struct osmo_msc_data {
+	/* Back pointer */
+	struct gsm_network *network;
+
 	/* Connection data */
 	char *bsc_token;
 	int msc_port;

openbsc/src/libcommon/gsm_data.c

@@ -267,6 +267,9 @@ struct gsm_network *gsm_network_init(uint16_t country_code, uint16_t network_cod
 		return NULL;
 	}
 
+	/* Init back pointer */
+	net->msc_data->network = net;
+
 	net->country_code = country_code;
 	net->network_code = network_code;
 	net->num_bts = 0;