BSC: do not flush RSL queue early in TC_chan_rel_a_reset()

When f_expect_chan_rel() is called after receiving the BSSMAP
RESET and DISC.ind f_expect_chan_rel() is called. The flush
parameter is not set, which means the default flush = true is
valid. This leads into an early flush of the RSL Queue and
tosses the RSL RELEASE REQUEST we expect, so the test can not
pass, even when the BSC sends the RLEASE REQUEST.

Looking further up in the code. IPA_RSL[0].clear is called,
so the Queue is flushed to get rid of unwanted messages from
the IMMEDIATE ASSIGN. There is no need to flush the queue
a second time anyway.

- Do not flush the RSL queue, set flush=false when calling
  f_expect_chan_rel()

Change-Id: I2962f741e0b13dec08ac6c918d326828beb65a6a
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 24df03f..086830a 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -710,7 +710,7 @@
 	[] BSSAP.receive(tr_BSSAP_DISC_ind(dt.sccp_conn_id, ?, ?)) { }
 	}
 
-	f_expect_chan_rel(0, dt.rsl_chan_nr);
+	f_expect_chan_rel(0, dt.rsl_chan_nr, false);
 	setverdict(pass);
 }