Fix enctype display in Leash

In KrbListTickets.cpp, change etype_string() to write its output to a
caller-supplied buffer, so that the session key enctype name and
ticket enctype name don't occupy the same static buffer.  Reported by
Oliver Freyermuth.

https://github.com/krb5/krb5/commit/5a00af5da3bdd137a21f2b59612ba5ef6dba1396
Author: Greg Hudson <ghudson@mit.edu>
Commit: 5a00af5da3bdd137a21f2b59612ba5ef6dba1396
Branch: master
 src/windows/leash/KrbListTickets.cpp |   23 +++++++++--------------
 1 files changed, 9 insertions(+), 14 deletions(-)