bcache:: fix repeated words in comments

Delete the redundant word 'we'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220919161647.81238-5-colyli@suse.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>