Commit 
3a50597de863 ("KEYS: Make the session and process keyrings
per-thread") removed the definition of the thread_group_cred structure,
but left a now unused pointer in struct cred.
Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
        struct key      *process_keyring; /* keyring private to this process */
        struct key      *thread_keyring; /* keyring private to this thread */
        struct key      *request_key_auth; /* assumed request_key authority */
-       struct thread_group_cred *tgcred; /* thread-group shared credentials */
 #endif
 #ifdef CONFIG_SECURITY
        void            *security;      /* subjective LSM security */