[krbdev.mit.edu #8498] Potential memory leak in prepare_error_as()

[Will Fiveash via RT]

In https://github.com/krb5/krb5/blob/master/src/kdc/do_as_req.c at line
848 there is:

e_data = calloc(count + 2, sizeof(*e_data));

and later starting at line 861:

    if (retval)
        return retval;

Looks like e_data can be leaked at that return.