md/raid5: avoid redundant bio clone in raid5_read_one_chunk

After enable io accounting, chunk read bio could be cloned twice which
is not good. To avoid such inefficiency, let's clone align_bio from
io_acct_set too, then we need only call md_account_bio in make_request
unconditionally.

Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>