Use an in-memory ccache to silence a compiler warning, for RT#6414.

--- krb5/src/slave/kprop.c

+++ krb5/src/slave/kprop.c

@@ -202,9 +202,8 @@ void PRS(argc, argv)

 void get_tickets(context)

     krb5_context context;

 {

-    char   buf[BUFSIZ], *def_realm;

+    char buf[] = "MEMORY:_kproptkt", *def_realm;

     krb5_error_code retval;

-    static char tkstring[] = "/tmp/kproptktXXXXXX";

     krb5_keytab keytab = NULL;

     /*

@@ -229,11 +228,8 @@ void get_tickets(context)

 #endif

     /*

-     * Initialize cache file which we're going to be using

+     * Initialize an in-memory cache for temporary use

      */

-    (void) mktemp(tkstring);

-    snprintf(buf, sizeof(buf), "FILE:%s", tkstring);

-

     retval = krb5_cc_resolve(context, buf, &ccache);

     if (retval) {

         com_err(progname, retval, _("while opening credential cache %s"), buf);