Debian Policy §10.4 says "Every script should use set -e or check
the exit status of every command", which is just generally good
advice.

Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D3478