minor edits after verifying refactored grbl on real hardware

motion_control.c

@@ -73,7 +73,6 @@ void mc_line(double x, double y, double z, float feed_rate, int invert_feed_rate
 	memcpy(position, target, sizeof(target)); // position[] = target[] 
 }
 
-
 // Execute an arc. theta == start angle, angular_travel == number of radians to go along the arc,
 // positive angular_travel means clockwise, negative means counterclockwise. Radius == the radius of the
 // circle in millimeters. axis_1 and axis_2 selects the circle plane in tool space. Stick the remaining