lxc-autostart: Respect -P

-P was only used for log setup and not when retrieving the container list.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
bdev.c: initialize a pointer to avoid build failures with -Werror=maybe-uninitialized

Signed-off-by: Leonid Isaev <lisaev@umail.iu.edu>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>