Pull to receive 9badce000e ("cgroup, writeback: don't enable cgroup
writeback on traditional hierarchies"). The commit adds
cgroup_on_dfl() usages in include/linux/backing-dev.h thus causing a
silent conflict with 9e10a130d9 ("cgroup: replace cgroup_on_dfl()
tests in controllers with cgroup_subsys_on_dfl()"). The conflict is
fixed during this merge.
Signed-off-by: Tejun Heo <tj@kernel.org>
c0522908d2