Sector-based blk_aio_readv() and blk_aio_writev() should die; switch
to byte-based blk_aio_preadv() and blk_aio_pwritev() instead.
As part of the cleanup, scsi_init_iovec() no longer needs to return
a value, and reword a comment.
[ kwolf: Fix read accounting change ]
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
03c90063cc