Fix krb5_cc_move() issues

Move init/copy/destroy fallback sequence from fcc_move() to
krb5_cc_move().

Make sure all backends's move() method calls krb5_cc_destroy() on the
source on success (and only on success).

In text_cc make sure that we can find in the destination the cred
stored into the source.

lib/krb5/krcache.c

@@ -1977,10 +1977,7 @@ krcc_move(krb5_context context, krb5_ccache from, krb5_ccache to)
     }
 
     update_change_time(context, now, krto);
-
-    krcc_destroy(context, from);
-    krcc_close(context, from);
-
+    krb5_cc_destroy(context, from);
     return 0;
 }