Copter: remove get_angle_targets_for_reporting fn

this saves a tiny amount of time by removing the memory copy of a
Vector3f

ArduCopter/GCS_Mavlink.pde

@@ -276,8 +276,7 @@ static void NOINLINE send_location(mavlink_channel_t chan)
 
 static void NOINLINE send_nav_controller_output(mavlink_channel_t chan)
 {
-    Vector3f targets;
-    get_angle_targets_for_reporting(targets);
+    const Vector3f &targets = attitude_control.angle_ef_targets();
     mavlink_msg_nav_controller_output_send(
         chan,
         targets.x / 1.0e2f,

ArduCopter/Log.pde

@@ -469,8 +469,7 @@ struct PACKED log_Attitude {
 // Write an attitude packet
 static void Log_Write_Attitude()
 {
-    Vector3f targets;
-    get_angle_targets_for_reporting(targets);
+    const Vector3f &targets = attitude_control.angle_ef_targets();
     struct log_Attitude pkt = {
         LOG_PACKET_HEADER_INIT(LOG_ATTITUDE_MSG),
         time_ms         : hal.scheduler->millis(),

ArduCopter/flight_mode.pde

@@ -327,8 +327,3 @@ print_flight_mode(AP_HAL::BetterStream *port, uint8_t mode)
     }
 }
 
-// get_angle_targets_for_reporting() - returns 3d vector of roll, pitch and yaw target angles for logging and reporting to GCS
-static void get_angle_targets_for_reporting(Vector3f& targets)
-{
-    targets = attitude_control.angle_ef_targets();
-}