testscripts/isofs.sh: cleanup

Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
testscripts/isofs.sh: use the new shell interface

Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
testscripts/isofs: make it quiet

All pass/fail checks are performed based on the exit value.
So we may freely redirect all unused output to /dev/null.

And exportfs always returns 0, so there is no point to execute it at all.

Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
Declare an iso9660 fs testcase based on isofs.sh

Script isofs.sh looks like a not bad candidate for
testing an iso9660 file system.

Therefore moved it into a separate directory and declared
a new test case entry in runtest/fs.

Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>