There are a couple of different schools of thought here. Some people say the rod should be in a straight line when the servo is at neutral. Some say it should be in a straight line at full deflection. I tend to go with the latter train of thought in which case your setup would be fine. One thing I do do though, 'specially on aileron servos (but I do it on all servos, even throttle) is to put a ball link on the servo arm end of the linkage. Helps tp prevent binding as the servo moves throughout its range of travel.