tweak to the Loiter N turns

ArduCopter/ArduCopter.pde

@@ -1309,8 +1309,7 @@ static void update_nav_wp()
 		if (loiter_delta < -180) loiter_delta += 360;
 
 		// sum the angle around the WP
-		loiter_sum += abs(loiter_delta);
-
+		loiter_sum += loiter_delta;
 
 		// create a virtual waypoint that circles the next_WP
 		// Count the degrees we have circulated the WP

ArduCopter/commands_logic.pde

@@ -454,7 +454,7 @@ static bool verify_loiter_turns()
 {
 	// have we rotated around the center enough times?
 	// -----------------------------------------------
-	if(loiter_sum > loiter_total) {
+	if(abs(loiter_sum) > loiter_total) {
 		loiter_total 	= 0;
 		loiter_sum		= 0;
 		//gcs_send_text_P(SEVERITY_LOW,PSTR("verify_must: LOITER orbits complete"));