sbitmap: remove stale comment in sbq_calc_wake_batch

After commit 10639737 ("sbitmap: fix batching wakeup"), we may wake
up more than one queue for each batch. Just remove stale comment that
we wake up only one queue for each batch.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240115145626.665562-1-shikemeng@huaweicloud.com


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