When writing kuids onto the wire first map them into the initial user
namespace.

When writing kgids onto the wire first map them into the initial user
namespace.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>