Check for osmo_fsm_register() error return value

Change-Id: Id2556cf01341b67735fff2685d2f7532f50a4850
diff --git a/ccid_common/iso7816_fsm.c b/ccid_common/iso7816_fsm.c
index 412bea7..c9eba8d 100644
--- a/ccid_common/iso7816_fsm.c
+++ b/ccid_common/iso7816_fsm.c
@@ -1609,8 +1609,8 @@
 
 static __attribute__((constructor)) void on_dso_load_iso7816(void)
 {
-	osmo_fsm_register(&iso7816_3_fsm);
-	osmo_fsm_register(&atr_fsm);
-	osmo_fsm_register(&tpdu_fsm);
-	osmo_fsm_register(&pps_fsm);
+	OSMO_ASSERT(osmo_fsm_register(&iso7816_3_fsm) == 0);
+	OSMO_ASSERT(osmo_fsm_register(&atr_fsm) == 0);
+	OSMO_ASSERT(osmo_fsm_register(&tpdu_fsm) == 0);
+	OSMO_ASSERT(osmo_fsm_register(&pps_fsm) == 0);
 }