erofs: get rid of raw bi_end_io() usage

erofs: get rid of raw bi_end_io() usage

These BIOs are actually harmless in practice, as they are all pseudo
BIOs and do not use advanced features like chaining.  Using the BIO
interface is a more friendly and unified approach for both bdev and
and file-backed I/Os (compared to awkward bvec interfaces).

Let's use bio_endio() instead.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>