When initializing a new set of builds, INDEX-NEW will be empty. When we
filter out /boot/kernel/linker.hints from this empty file, we will be left
with... an empty file. Unfortunately, fgrep, having read no lines and
produced no output, returns an exit status of 1, which sh -e interprets
as an error.

Add a || true to the fgrep added in r276160 in order to unbreak init
builds.

Pointy Hat to: cperciva