Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"

Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"

[ Upstream commit b0beb28097fa04177b3769f4bb7a0d0d9c4ae76e ]

This reverts commit c58c1f83436b501d45d4050fd1296d71a9760bcb.

io_uring does do the right thing for this case, and we're still returning
-EAGAIN to userspace for the cases we don't support. Revert this change
to avoid doing endless spins of resubmits.

Cc: stable@vger.kernel.org # v5.6
Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>