dm: Refactor is_abnormal_io()

Use a single switch-case to simplify is_abnormal_io() and make this
function more readable and easier to modify.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240704052816.623865-3-dlemoal@kernel.org


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