bit_reader.h: cosmetics: fix a typo

Change-Id: I1ba09124700b3120f18eb3705eb5ba805feb2ca0
(cherry picked from commit 79b5bdbfde6773e95744155853ecb880889b931a)
update ChangeLog

Change-Id: I32a22786f99d0c239761a362485a4a91c783851b