NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index c9f6503..adc3c40 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -1074,7 +1074,7 @@ static void rpc_release_resources_task(struct rpc_task *task)
 {
 	xprt_release(task);
 	if (task->tk_msg.rpc_cred) {
-		put_rpccred(task->tk_msg.rpc_cred);
+		put_cred(task->tk_msg.rpc_cred);
 		task->tk_msg.rpc_cred = NULL;
 	}
 	rpc_task_release_client(task);