APMrover2: use ARRAY_SIZE macro

APMrover2/APMrover2.cpp

@@ -100,7 +100,7 @@ void Rover::setup()
     init_ardupilot();
 
     // initialise the main loop scheduler
-    scheduler.init(&scheduler_tasks[0], sizeof(scheduler_tasks)/sizeof(scheduler_tasks[0]));
+    scheduler.init(&scheduler_tasks[0], ARRAY_SIZE(scheduler_tasks));
 }
 
 /*

APMrover2/Log.cpp

@@ -394,7 +394,7 @@ const LogStructure Rover::log_structure[] PROGMEM = {
 
 void Rover::log_init(void)
 {
-	DataFlash.Init(log_structure, sizeof(log_structure)/sizeof(log_structure[0]));
+	DataFlash.Init(log_structure, ARRAY_SIZE(log_structure));
     if (!DataFlash.CardInserted()) {
         gcs_send_text_P(SEVERITY_LOW, PSTR("No dataflash card inserted"));
         g.log_bitmask.set(0);