Previously, stinit returned zero even if it fails to set the options.
This patch changes the return value to one if one or more of the options
can't be set for a device if the tape numbers are given on command line.
If no numbers are given, stinit returns zero (as before this patch).
After this change, scripts (udev rules) can more easily detect when
stinit fails.
Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
The embedding of tests in the Makefile works only for that is there
today - a few `--version` and `stinit -p` calls. For expanding the
test coverage, as much as it can be done for `mt`, let's use a proper
shell test runner. `shelltestrunner` is available in Debian/Ubuntu, so
it's likely to be available in other distributions too, and as such
should not be a big barrier to contribution.
