bsc: TC_paging_500req: Validate initial transmissions have higher prio

After osmo-bsc Change-Id I1ae6d97152c458247bc538233b97c2d245196359,
initial requests are prioritized over retransmits.
Before that feature was in place, when sending 500 requests in this test
to the BSC, it could happen that the paging scheduler triggered (every
500ms) before all the 500 requests were received at the BSC. As a
result, the scheduler would put some requests to the end of the queue
after sending an initial request for it towards the BTS. If later more
requests where received from TTCN3, they'd be put at the end, after the
retransmissions.
As a result, the emulated BTS would in general receive retranmits for
the first bunch of requests before receiving the initial transmit of the
later requests.
Ths is no longer the case since the osmo-bsc is prioritizing now the
initial requests. Hence, we'll only start receiving retransmits after
all the new paging requests are received.

Depends: osmo-bsc.git I1ae6d97152c458247bc538233b97c2d245196359
Change-Id: I5876f828b43e1e51bd892ce3c9a4dbed6b53f066
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 5779990..2858cdf 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -3622,6 +3622,9 @@
 		if (rx_paging_done[imsi_idx] == false) {
 			rx_paging_done[imsi_idx] := true;
 			rx_paging_num := rx_paging_num + 1;
+		} else {
+			setverdict(fail, "Retrans happened before Rx initial trans for all reqs. ", rx_paging_num);
+			mtc.stop;
 		}
 		if (rx_paging_num < num_subscribers) {
 			repeat;