cosmetic: rename sccp_rx_udt and sccp_rx_dt to a_*

These rx functions are only used for the A interface, hence the names should
not suggest general SCCP rx (which Iu also has).

Change-Id: I6815c3d4dea4c2abfdff1cf0239ada6a9254f351
diff --git a/include/osmocom/msc/a_iface_bssap.h b/include/osmocom/msc/a_iface_bssap.h
index 237c618..79b8390 100644
--- a/include/osmocom/msc/a_iface_bssap.h
+++ b/include/osmocom/msc/a_iface_bssap.h
@@ -34,8 +34,8 @@
 };
 
 /* Receive incoming connection less data messages via sccp */
-void sccp_rx_udt(struct osmo_sccp_user *scu, const struct a_conn_info *a_conn_info, struct msgb *msg);
+void a_sccp_rx_udt(struct osmo_sccp_user *scu, const struct a_conn_info *a_conn_info, struct msgb *msg);
 
 /* Receive incoming connection oriented data messages via sccp */
-int sccp_rx_dt(struct osmo_sccp_user *scu, const struct a_conn_info *a_conn_info, struct msgb *msg);
+int a_sccp_rx_dt(struct osmo_sccp_user *scu, const struct a_conn_info *a_conn_info, struct msgb *msg);