cosmetic: rename gsm_subscriber_connection->conn_fsm to ->fi

Match osmo-bsc's naming of the subscriber connection's FSM instance; 'conn->fi'
makes more sense anyway than 'conn->conn_fsm'.

BTW, an upcoming commit will do away with the legacy from libbsc/libmsc duality
and firmly glue the conn allocation to the fi.

Related: OS#3122
Change-Id: If442f2ba78d9722b1065ec30c9a13f372b6a8caa
diff --git a/tests/msc_vlr/msc_vlr_test_reject_concurrency.c b/tests/msc_vlr/msc_vlr_test_reject_concurrency.c
index 08fc9e7..ceab109 100644
--- a/tests/msc_vlr/msc_vlr_test_reject_concurrency.c
+++ b/tests/msc_vlr/msc_vlr_test_reject_concurrency.c
@@ -109,7 +109,7 @@
 	cm_service_result_sent = RES_NONE;
 	ms_sends_msg("05247803305886089910070000006402");
 	OSMO_ASSERT(g_conn);
-	OSMO_ASSERT(g_conn->conn_fsm);
+	OSMO_ASSERT(g_conn->fi);
 	OSMO_ASSERT(g_conn->vsub);
 	VERBOSE_ASSERT(cm_service_result_sent, == RES_ACCEPT, "%d");
 	EXPECT_ACCEPTED(true);