[ein0p]

I was confused, actually, not you. The output was:

cat /sys/dev/block/8:176/queue/scheduler

[mq-deadline] none

However, this output does not mean what I thought it did - it means that mq-deadline is in use.

If I do

echo "none" | sudo tee /sys/dev/block/8:176/queue/scheduler

This changes to

cat /sys/dev/block/8:176/queue/scheduler

[none] mq-deadline