changeset fb5772cb ("blkio-controller.txt: Remove references to CFQ")
removed cgroup references to CFQ, but it kept one left. Get rid of
it.

Fixes: fb5772cb ("blkio-controller.txt: Remove references to CFQ")
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>