install/autodetect: try to avoid a race condition with udev

install/autodetect: give up on module autodetection when encountering an error

Move the find -exec sort command outside process substitution to allow catching it when it fails. If it does fail, return early to prevent a situation where the initramfs is missing needed modules.

Give up if auto_modules returns no modules. If no in-use modules are detected, then there is nothing for the hook to do.

Fixes #177 (closed)

install/autodetect: retry looking at uevents

If the first time does not succeed, retry again, but only once. This will hopefully avoid a race condition with udev.