rename some RAN conn related stuff to ran_conn_*

Following previous rename of gsm_subscriber_connection:

Some functions and #defines are still called like "msc_conn" or just "msc_",
while they are clearly about a RAN conn.

To avoid confusion with the future separate concepts of MSC roles and a RAN
connection, rename all those to match the common "ran_conn" prefix.

Change-Id: Ia17a0a35f11911e00e19cafb5d7828d729a69640
diff --git a/src/libmsc/gsm_04_11.c b/src/libmsc/gsm_04_11.c
index d214f2e..d012443 100644
--- a/src/libmsc/gsm_04_11.c
+++ b/src/libmsc/gsm_04_11.c
@@ -148,7 +148,7 @@
 	switch (event) {
 	case GSM_PAGING_SUCCEEDED:
 		/* Associate transaction with established connection */
-		trans->conn = ran_conn_get(conn, MSC_CONN_USE_TRANS_SMS);
+		trans->conn = ran_conn_get(conn, RAN_CONN_USE_TRANS_SMS);
 		/* Confirm successful connection establishment */
 		gsm411_smc_recv(&trans->sms.smc_inst,
 			GSM411_MMSMS_EST_CNF, NULL, 0);
@@ -1010,7 +1010,7 @@
 	conn = connection_for_subscr(vsub);
 	if (conn) {
 		/* Associate transaction with connection */
-		trans->conn = ran_conn_get(conn, MSC_CONN_USE_TRANS_SMS);
+		trans->conn = ran_conn_get(conn, RAN_CONN_USE_TRANS_SMS);
 		/* Generate unique RP Message Reference */
 		trans->sms.sm_rp_mr = conn->next_rp_ref++;
 	}
@@ -1140,7 +1140,7 @@
 		gsm411_smr_init(&trans->sms.smr_inst, 0, 1,
 			gsm411_rl_recv, gsm411_mn_send);
 
-		trans->conn = ran_conn_get(conn, MSC_CONN_USE_TRANS_SMS);
+		trans->conn = ran_conn_get(conn, RAN_CONN_USE_TRANS_SMS);
 		trans->dlci = OMSC_LINKID_CB(msg); /* DLCI as received from BSC */
 
 		new_trans = 1;