Initialize zero before using it in unwrap_des().

Heimdal since fc702a97f5 (August 2009)
can't process DES wrap tokens unless the stack garbage in the zero
array happens to be all zeros.

Signed-off-by: Love Hörnquist Åstrand <lha@h5l.org>

lib/gssapi/krb5/unwrap.c

@@ -98,6 +98,7 @@ unwrap_des
   if(cstate) {
       /* decrypt data */
       memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
+      memset (&zero, 0, sizeof(zero));
 
       for (i = 0; i < sizeof(deskey); ++i)
 	  deskey[i] ^= 0xf0;