CRED: Separate task security context from task_struct

Separate the task security context from task_struct.  At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.

Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.

With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index bb93946..a5e14e8 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -57,17 +57,17 @@
 static void
 nfs4_save_user(uid_t *saveuid, gid_t *savegid)
 {
-	*saveuid = current->fsuid;
-	*savegid = current->fsgid;
-	current->fsuid = 0;
-	current->fsgid = 0;
+	*saveuid = current->cred->fsuid;
+	*savegid = current->cred->fsgid;
+	current->cred->fsuid = 0;
+	current->cred->fsgid = 0;
 }
 
 static void
 nfs4_reset_user(uid_t saveuid, gid_t savegid)
 {
-	current->fsuid = saveuid;
-	current->fsgid = savegid;
+	current->cred->fsuid = saveuid;
+	current->cred->fsgid = savegid;
 }
 
 static void