Fix sam2 client preauth after salt changes

Commit bc096a77ffdab283d77c2e0fc1fdd15b9f77eb41 altered the internal
contracts relating to salts, but neglected to adjust the sam2 preauth
code to match.  Do that now.

https://github.com/krb5/krb5/commit/787cc1e24117e57a9173aaaa16935f6488eb3fec
Author: Greg Hudson <ghudson@mit.edu>
Commit: 787cc1e24117e57a9173aaaa16935f6488eb3fec
Branch: master
 src/lib/krb5/krb/preauth_sam2.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)