chan_alloc: Delete T3101 on lchan_free as well

If a RF channel is assigned but no response is ever heard from
the phone, we will receive a CONNECTION FAIL from the BTS,
triggering a RF release freeing the channel. Then sometime later,
T3101 will expire as well and free the channel again ...

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/openbsc/src/chan_alloc.c b/openbsc/src/chan_alloc.c
index 786e8b1..a23192a 100644
--- a/openbsc/src/chan_alloc.c
+++ b/openbsc/src/chan_alloc.c
@@ -251,6 +251,7 @@
 
 	/* stop the timer */
 	bsc_del_timer(&lchan->release_timer);
+	bsc_del_timer(&lchan->T3101);
 
 	/* clear cached measuement reports */
 	lchan->meas_rep_idx = 0;