CVE-2017-13047/ES-IS: put an existing bounds check right

The bounds check in esis_print() tested one pointer at the beginning of
a loop that incremented another, make the trivial fix. While at it, make
the function print a standard marker when it detects truncated data and
update some existing ES-IS tests respectively.

This fixes a buffer over-read discovered by Bhargava Shastry,
SecT/TU Berlin.

Add a test using the capture file supplied by the reporter(s).