tests: Normalize trailing white space in test output completely
Commit
37ff377 stripped trailing white space in test output, except
for journal.log, where it stripped it only from player output. This
misses the space preceeding player empty output, and doesn't cover
equally annoying trailing white space elsewhere, such as the space
preceeding empty input and trailing white space in prompts. Testing
the latter could be marginally useful, but let's keep things simple,
and strip all trailing white space for now.
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>