handover: Call bsc_handover_clear from gsm0808_clear

The bsc_handover_clear will release an in-progress handover
and free the lchana and the data associated with this handover
diff --git a/openbsc/src/chan_alloc.c b/openbsc/src/chan_alloc.c
index 675cbbb..dda5ff2 100644
--- a/openbsc/src/chan_alloc.c
+++ b/openbsc/src/chan_alloc.c
@@ -478,13 +478,8 @@
 	}
 
 
-	/* Release a handover that might be in operation */
-	if (conn->ho_lchan) {
-		conn->ho_lchan->conn = NULL;
-		lchan_release(conn->ho_lchan, 0, 1);
-		conn->ho_lchan = NULL;
-	}
-
+	if (conn->ho_lchan)
+		LOGP(DNM, LOGL_ERROR, "The ho_lchan should have been cleared.\n");
 
 	lchan = conn->lchan;
 	talloc_free(conn);