Respect VOLATILE_LOG_DIR variable. In this way, if the user overrides
this variable to be any valid boolean false value, /var/log on the final
image would reside on persistent storage.
[YOCTO #6132]
(From OE-Core rev: fc19114ca409fc3178ae5cbb44db875b12eeedfc)
Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>