tests/gsm0808: fix assert()s in test_gsm0808_dec_cell_id_list_srvcc()

Change-Id: I6aa901fd706c74fe86b65a474c1d82803f28eeb4
Fixes: CID#274663
diff --git a/tests/gsm0808/gsm0808_test.c b/tests/gsm0808/gsm0808_test.c
index aa086a2..ed99245 100644
--- a/tests/gsm0808/gsm0808_test.c
+++ b/tests/gsm0808/gsm0808_test.c
@@ -1296,8 +1296,8 @@
 
 	rc = gsm0808_dec_cell_id_list2(&dec_cil, enc_cil, sizeof(enc_cil));
 	OSMO_ASSERT(rc == sizeof(enc_cil));
-	OSMO_ASSERT(dec_cil.id_discr = CELL_IDENT_SAI);
-	OSMO_ASSERT(dec_cil.id_list_len = 1);
+	OSMO_ASSERT(dec_cil.id_discr == CELL_IDENT_SAI);
+	OSMO_ASSERT(dec_cil.id_list_len == 1);
 }
 
 static void test_gsm0808_enc_dec_cell_id_list_lac(void)