test-ls.sh: take only the first 10 chars from ls -l's mode string.

Since ls -l's mode string may not be separated from the next field by
a space (i.e. when ACLs, etc. are involved), take only the first 10
characters for now when retrieving the symlink mode string (cf.
30d9027cc5444f038d38927219dc59e3b69fa219).

Thanks to Mark J Hewitt <mjh@idnet.com> for pointing out the problem
and testing the solution.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>