Use an in-memory ccache to silence a compiler warning.

diff -up krb5-1.7/src/slave/kprop.c krb5-1.7/src/slave/kprop.c
--- krb5-1.7/src/slave/kprop.c	2008-12-01 12:09:59.000000000 -0500
+++ krb5-1.7/src/slave/kprop.c	2009-06-04 14:14:10.000000000 -0400
@@ -211,9 +211,8 @@ void PRS(argc, argv)
 void get_tickets(context)
     krb5_context context;
 {
-	char   buf[BUFSIZ];
+	char buf[] = "MEMORY:_kproptkt";
 	krb5_error_code retval;
-	static char tkstring[] = "/tmp/kproptktXXXXXX";
 	krb5_keytab keytab = NULL;
 
 	/*
@@ -238,11 +237,8 @@ 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",