netprio_cgroup: convert away from cftype->read_map()
netprio_cgroup: convert away from cftype->read_map()

In preparation of conversion to kernfs, cgroup file handling is being
consolidated so that it can be easily mapped to the seq_file based
interface of kernfs.

cftype->read_map() doesn't add any value and being replaced with
->read_seq_string().  Update read_priomap() to use ->read_seq_string()
instead.

This patch doesn't make any visible behavior changes.

Signed-off-by: Tejun Heo <546b05909706652891a87f7bfe385ae147f61f91@kernel.org>
Acked-by: Neil Horman <3316dc2d77df57653443c0391a5296176d6ca9c3@tuxdriver.com>
Acked-by: Daniel Wagner <53566a40310e7120a373d88c94d924839fd4b1fa@bmw-carit.de>
Acked-by: Li Zefan <a8167b9d27aca9c6624754deb52c4c6420eded04@huawei.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs