commit 3e41871046bfe0ba7d122a1f14f0c1db2dca0256
author Tejun Heo <tj@kernel.org> Tue Aug 18 14:55:10 2015 -0700
committer Jens Axboe <axboe@fb.com> Tue Aug 18 15:49:16 2015 -0700
tree f6b33773063f53df1ab0751199a7f6830f6398bf
parent 4c55f4f9ad3001ac1fefdd8d8ca7641d18558e23

blkcg: make blkcg_activate_policy() allow NULL ->pd_init_fn

blkg_create() allows NULL ->pd_init_fn() but blkcg_activate_policy()
doesn't.  As both in-kernel policies implement ->pd_init_fn, it
currently doesn't break anything.  Update blkcg_activate_policy() so
that its behavior is consistent with blkg_create().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>