rename gsm_subscriber_connection to ran_conn

In preparation for inter-BSC and inter-MSC handover, we need to separate the
subscriber management logic from the actual RAN connections. What better time
to finally rename gsm_subscriber_connection.

* Name choice:

In 2G, this is a connection to the BSS, but even though 3GPP TS commonly talk
of "BSS-A" and "BSS-B" when explaining handover, it's not good to call it
"bss_conn": in 3G a BSS is called RNS, IIUC.

The overall term for 2G (GERAN) and 3G (UTRAN) is RAN: Radio Access Network.

* Rationale:

A subscriber in the MSC so far has only one RAN connection, but e.g. for
inter-BSC handover, a second one needs to be created to handover to. Most of
the items in the former gsm_subscriber_connection are actually related to the
RAN, with only a few MM and RTP related items. So, as a first step, just rename
it to ran_conn, to cosmetically prepare for moving the not strictly RAN related
items away later.

Also:

- Rename some functions from msc_subscr_conn_* to ran_conn_*
- Rename "Subscr_Conn" FSM instance name to "RAN_conn"
- Rename SUBSCR_CONN_* to RAN_CONN_*

Change-Id: Ic595f7a558d3553c067f77dc67543ab59659707a
diff --git a/include/osmocom/msc/transaction.h b/include/osmocom/msc/transaction.h
index 762eeea..0760c07 100644
--- a/include/osmocom/msc/transaction.h
+++ b/include/osmocom/msc/transaction.h
@@ -38,7 +38,7 @@
 	struct vlr_subscr *vsub;
 
 	/* The associated connection we are using to transmit messages */
-	struct gsm_subscriber_connection *conn;
+	struct ran_conn *conn;
 
 	/* reference from MNCC or other application */
 	uint32_t callref;
@@ -98,11 +98,11 @@
 
 
 
-struct gsm_trans *trans_find_by_id(struct gsm_subscriber_connection *conn,
+struct gsm_trans *trans_find_by_id(struct ran_conn *conn,
 				   uint8_t proto, uint8_t trans_id);
 struct gsm_trans *trans_find_by_callref(struct gsm_network *net,
 					uint32_t callref);
-struct gsm_trans *trans_find_by_sm_rp_mr(struct gsm_subscriber_connection *conn,
+struct gsm_trans *trans_find_by_sm_rp_mr(struct ran_conn *conn,
 					 uint8_t sm_rp_mr);
 
 struct gsm_trans *trans_alloc(struct gsm_network *net,
@@ -113,7 +113,7 @@
 
 int trans_assign_trans_id(struct gsm_network *net, struct vlr_subscr *vsub,
 			  uint8_t protocol, uint8_t ti_flag);
-struct gsm_trans *trans_has_conn(const struct gsm_subscriber_connection *conn);
-void trans_conn_closed(struct gsm_subscriber_connection *conn);
+struct gsm_trans *trans_has_conn(const struct ran_conn *conn);
+void trans_conn_closed(struct ran_conn *conn);
 
 #endif