examples/worker_collections: minor fixes

examples/worker_collections/worker_list_example.c

@@ -21,7 +21,12 @@
 
 int main()
 {
-	starpu_init(NULL);
+	int ret;
+
+	ret = starpu_init(NULL);
+	if (ret == -ENODEV)
+		return 77;
+	STARPU_CHECK_RETURN_VALUE(ret, "starpu_init");
 
 	int procs[STARPU_NMAXWORKERS];
 	unsigned ncpus =  starpu_cpu_worker_get_count();

examples/worker_collections/worker_tree_example.c

@@ -63,7 +63,7 @@ int main()
 
 	double timing = (end_time - start_time) / 1000;
 
-	int i;
+	unsigned i;
 	for(i = 0; i < ncpus; i++)
 	{
 		int added = co->add(co, procs[i]);