bssgp: Fix call to llist_entry in fc_queue_timer_cfg

Currently the DL sometimes hangs and sometimes a lot of messages
(still not able to send PDU) are logged. This is caused by an invalid
timer delay computation, setting msecs either to 0 or to some big value.

This is due to an '&' operator at the wrong place, accessing some
parts in fc instead of the first element of the list.

This commit fixes that issue.

Sponsored-by: On-Waves ehf
diff --git a/src/gb/gprs_bssgp.c b/src/gb/gprs_bssgp.c
index 4c93b69..fe4fcca 100644
--- a/src/gb/gprs_bssgp.c
+++ b/src/gb/gprs_bssgp.c
@@ -628,7 +628,7 @@
 	if (llist_empty(&fc->queue))
 		return 0;
 
-	fcqe = llist_entry(&fc->queue.next, struct bssgp_fc_queue_element,
+	fcqe = llist_entry(fc->queue.next, struct bssgp_fc_queue_element,
 			   list);
 
 	if (fc->bucket_leak_rate != 0) {