userns: Teach security_path_chown to take kuids and kgids

Don't make the security modules deal with raw user space uid and
gids instead pass in a kuid_t and a kgid_t so that security modules
only have to deal with internal kernel uids and gids.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: James Morris <james.l.morris@oracle.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/security/security.c b/security/security.c
index 860aeb3..f9a2f2e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -434,7 +434,7 @@
 	return security_ops->path_chmod(path, mode);
 }
 
-int security_path_chown(struct path *path, uid_t uid, gid_t gid)
+int security_path_chown(struct path *path, kuid_t uid, kgid_t gid)
 {
 	if (unlikely(IS_PRIVATE(path->dentry->d_inode)))
 		return 0;