sysmo: fix wrong FN jumps in rx RA.ind

There's no need for setting the FN in RA.ind since we anyway already
receive a DATA.ind beforehand.
Furthermore, the applied delay of 5 in the call is not really used at
all.

Change-Id: I437f4f95d054aea96bec3b9343e495451020ff3c
diff --git a/src/bts.cpp b/src/bts.cpp
index c1cee17..dc4159c 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -305,7 +305,7 @@
 	return (fn + GSM_MAX_FN * 3 / 2 - to) % GSM_MAX_FN - GSM_MAX_FN/2;
 }
 
-void bts_set_current_block_frame_number(struct gprs_rlcmac_bts *bts, int fn, unsigned max_delay)
+void bts_set_current_block_frame_number(struct gprs_rlcmac_bts *bts, int fn)
 {
 	int delay = 0;
 	const int late_block_delay_thresh = 13;