[PATCH] pidns: remove the useless function is_container_init

[Eric W. Biederman]

"Serge E. Hallyn" <serge at hallyn.com> writes:

> Quoting Gao feng (gaofeng at cn.fujitsu.com):
>> since commit 1cdcbec1a3372c0c49c59d292e708fd07b509f18,
>> is_container_init has no used for a long time.
>> 
>> just remove it.
>
> Only thing is it's being exported, so I think it needs to go through
> deprecation.

Exports do not create an ABI.  No internal kernel users are enough.

Eric