Fix populate_krb5_db_entry() princ_ent init

The most recent commit introduced a new variable princ_ent in
populate_krb5_db_entry().  princ_ent is cleaned up by the function's
cleanup label, so it must be initialized before any "goto cleanup"
statements.

https://github.com/krb5/krb5/commit/9526953f36b39323ec07448a5f218d27c6f1c76f
Author: Greg Hudson <ghudson@mit.edu>
Commit: 9526953f36b39323ec07448a5f218d27c6f1c76f
Branch: master
 src/plugins/kdb/ldap/libkdb_ldap/ldap_misc.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)