add LOG_TRANS, proper context for all transactions

Change-Id: I2e60964d7a3c06d051debd1c707051a0eb3101ba
diff --git a/src/libmsc/transaction.c b/src/libmsc/transaction.c
index b38c152..665ad46 100644
--- a/src/libmsc/transaction.c
+++ b/src/libmsc/transaction.c
@@ -110,18 +110,14 @@
 			      uint8_t protocol, uint8_t trans_id,
 			      uint32_t callref)
 {
-	struct gsm_trans *trans;
+	struct gsm_trans *trans = NULL; /* (NULL for LOG_TRANS() before allocation) */
 
 	/* a valid subscriber is indispensable */
 	if (vsub == NULL) {
-		LOGP(DVLR, LOGL_ERROR,
-		     "unable to alloc transaction, invalid subscriber (NULL)\n");
+		LOG_TRANS(trans, LOGL_ERROR, "unable to alloc transaction, invalid subscriber (NULL)\n");
 		return NULL;
 	}
 
-	DEBUGP(DCC, "(ti %02x sub %s callref %x) New transaction\n",
-	       trans_id, vlr_subscr_name(vsub), callref);
-
 	trans = talloc_zero(tall_trans_ctx, struct gsm_trans);
 	if (!trans)
 		return NULL;
@@ -135,6 +131,7 @@
 	trans->net = net;
 	llist_add_tail(&trans->entry, &net->trans_list);
 
+	LOG_TRANS(trans, LOGL_DEBUG, "New transaction\n");
 	return trans;
 }
 
@@ -146,6 +143,8 @@
 	enum ran_conn_use conn_usage_token;
 	struct ran_conn *conn;
 
+	LOG_TRANS(trans, LOGL_DEBUG, "Freeing transaction\n");
+
 	switch (trans->protocol) {
 	case GSM48_PDISC_CC:
 		_gsm48_cc_trans_free(trans);