msc: Add net parameter to trans_alloc

The trans_alloc function still uses the subscr object to access the
network object.

This patch adds an explicit net parameter to this function and
removes the access to subscr to obtain it.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/libmsc/gsm_04_11.c b/openbsc/src/libmsc/gsm_04_11.c
index bc9d59e..9941e6b 100644
--- a/openbsc/src/libmsc/gsm_04_11.c
+++ b/openbsc/src/libmsc/gsm_04_11.c
@@ -765,7 +765,8 @@
 
 	if (!trans) {
 		DEBUGP(DLSMS, " -> (new transaction)\n");
-		trans = trans_alloc(conn->subscr, GSM48_PDISC_SMS,
+		trans = trans_alloc(conn->bts->network, conn->subscr,
+				    GSM48_PDISC_SMS,
 				    transaction_id, new_callref++);
 		if (!trans) {
 			DEBUGP(DLSMS, " -> No memory for trans\n");
@@ -838,7 +839,8 @@
 	DEBUGP(DLSMS, "send_sms_lchan()\n");
 
 	/* FIXME: allocate transaction with message reference */
-	trans = trans_alloc(conn->subscr, GSM48_PDISC_SMS,
+	trans = trans_alloc(conn->bts->network, conn->subscr,
+			    GSM48_PDISC_SMS,
 			    transaction_id, new_callref++);
 	if (!trans) {
 		LOGP(DLSMS, LOGL_ERROR, "No memory for trans\n");