syscalls/keyctl03: Add new regression test

Fixed by:
commit f05819df10d7b09f6d1eb6f8534a8f68e5a4fe61
Author: David Howells <dhowells@redhat.com>
Date:   Thu Oct 15 17:21:37 2015 +0100

    KEYS: Fix crash when attempt to garbage collect
          an uninstantiated keyring

Signed-off-by: Guangwen Feng <fenggw-fnst@cn.fujitsu.com>
4 files changed