INSTDIR has everything that will be installed anyway, so ideally the
file search patch should only be INSTDIR + whatever is needed to get the
Package file lists; especially WORKDIR seems inappropriate there.

The exception is extension .oxt files which apparently are not in
INSTDIR; not sure what to do about those.

Change-Id: I2477c25ab9fcf953fae9c219e76c467e14729cda