scripts: always use printf with embedded gettext
This addresses two problems:
1) echo's behavior is inconsistent when dealing with flags, and can
potentially be problematic.
$ echo -n
$ echo -- -n
-- -n
2) Always using the end of options markers prevents translated strings
from throwing errors, as shown in FS#28069.
The remaining "inconsistencies" are because printf is being used in a
guaranteed safe manner, e.g.
printf '%s\n' "$(gettext "--this can never break")"
Signed-off-by: Dave Reisner <dreisner@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>