execute: set init_path when existing init is found
execute: set init_path when existing init is found

I'm not really sure we should be looking in the rootfs for an existing
init, but I'll send a much more invasive patch to correct that. For now,
let's just make sure we set init_path when we find one, so that later in
execute_start() we don't bail.

Signed-off-by: Tycho Andersen <6b523322678240882acbb4da5312a12d8cd0082d@tycho.ws>

ss1h2a3tw/lxc,hallyn/lxc,hallyn/lxc,caglar10ur/lxc,ss1h2a3tw/lxc,caglar10ur/lxc,caglar10ur/lxc,ss1h2a3tw/lxc,hallyn/lxc