src: use osmo_timer_setup()

Use new function available in libosmocore to set up timers. Compile
tested only.

Change-Id: Ibcfd915688e97d370a888888a83a7c95cbe16819
diff --git a/openbsc/src/libbsc/handover_logic.c b/openbsc/src/libbsc/handover_logic.c
index ffcca66..4dd913b 100644
--- a/openbsc/src/libbsc/handover_logic.c
+++ b/openbsc/src/libbsc/handover_logic.c
@@ -216,8 +216,7 @@
 
 	/* start T3103.  We can continue either with T3103 expiration,
 	 * 04.08 HANDOVER COMPLETE or 04.08 HANDOVER FAIL */
-	ho->T3103.cb = ho_T3103_cb;
-	ho->T3103.data = ho;
+	osmo_timer_setup(&ho->T3103, ho_T3103_cb, ho);
 	osmo_timer_schedule(&ho->T3103, 10, 0);
 
 	/* create a RTP connection */