Try to reuse the configured paths as much as possible. Unfortunately, to
be able to fully expand some variable (e.g. `bindir`), these files must
be expanded by make, not by configure. This adds some complexity:
https://www.gnu.org/software/automake/manual/html_node/Scripts.html
Mostly fixed omitted double quotes, some conversion of $(eval ..) to $(()).
Left the echo -n untouched, shellcheck complains about not being standard in
/bin/sh. Also, seems like some code is dublicated in ethercatctl.in and
init.d/ethercat.in.
Signed-off-by: Matthias Schoepfer <m.schoepfer@rethinkrobotics.com>
Nicola Fontana
Matthias Schoepfer
Florian Pose