doc: Update Japanese lxc.container.conf(5) for guidance of lxc.mount.entry

Update for commit 6191f4f

Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
doc: Update Japanese lxc.container.conf(5) for lxc.rootfs conventions

Update for commit f1c26f2

Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>