Replace sleep(x) by sleep(x*1000000), for sleep() is not available on Windows.

tests/sched_policies/execute_all_tasks.c

@@ -60,7 +60,7 @@ dummy(void *buffers[], void *args)
 {
 	(void) buffers;
 	(void) args;
-	sleep(1);
+	usleep(1000000);
 }
 
 static int

tests/sched_policies/simple_deps.c

@@ -32,7 +32,7 @@ dummy(void *buffers[], void *args)
 {
 	(void) buffers;
 	(void) args;
-	sleep(1);
+	usleep(1000000);
 }
 
 static int