Remove extra comment at TableAmRoutine.scan_analyze_next_block
The extra comment was accidentally copied here by
6377e12a from
heapam_scan_analyze_next_block().
Reported-by: Matthias van de Meent
Discussion: https://postgr.es/m/CAEze2WjC5PiweG-4oe0hB_Zr59iF3tRE1gURm8w4Cg5b6JEBGw%40mail.gmail.com