blk-cgroup: hold queue_lock when removing blkg->q_node
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2217205
Signed-off-by: Ming Lei ming.lei@redhat.com
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2217205
Signed-off-by: Ming Lei ming.lei@redhat.com