block: don't print I/O error warning for dead disks

When a disk has been marked dead, don't print warnings for I/O errors
as they are very much expected.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220323163815.1526998-1-hch@lst.de


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