block: remove unneeded return value of bio_check_ro()

bio_check_ro() always return false now. Remove this unneeded return value
and cleanup the sole caller. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Link: https://lore.kernel.org/r/20220905102754.1942-1-linmiaohe@huawei.com


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