mgcp: Move the rtp state into a struct

Use a struct to group the rtp state for the up and the down
link of the bts.
diff --git a/openbsc/src/mgcp/mgcp_vty.c b/openbsc/src/mgcp/mgcp_vty.c
index 45df0a2..a179b7a 100644
--- a/openbsc/src/mgcp/mgcp_vty.c
+++ b/openbsc/src/mgcp/mgcp_vty.c
@@ -87,8 +87,8 @@
 			i, endp->ci,
 			ntohs(endp->net_rtp), ntohs(endp->net_rtcp),
 			ntohs(endp->bts_rtp), ntohs(endp->bts_rtcp),
-			inet_ntoa(endp->bts), endp->in_bts, endp->bts_lost_no,
-			endp->in_remote, endp->net_lost_no,
+			inet_ntoa(endp->bts), endp->in_bts, endp->bts_state.lost_no,
+			endp->in_remote, endp->net_state.lost_no,
 			VTY_NEWLINE);
 	}