SUNRPC: Remove the tk_auth macro...

We should almost always be deferencing the rpc_auth struct by means of the
credential's cr_auth field instead of the rpc_clnt->cl_auth anyway. Fix up
that historical mistake, and remove the macro that propagated it.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index cd3ca7b..7fcc78f 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -223,7 +223,7 @@
 static int
 nfs_xdr_readargs(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
 {
-	struct rpc_auth	*auth = req->rq_task->tk_auth;
+	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
 	unsigned int replen;
 	u32 offset = (u32)args->offset;
 	u32 count = args->count;
@@ -380,7 +380,7 @@
 nfs_xdr_readdirargs(struct rpc_rqst *req, __be32 *p, struct nfs_readdirargs *args)
 {
 	struct rpc_task	*task = req->rq_task;
-	struct rpc_auth	*auth = task->tk_auth;
+	struct rpc_auth	*auth = task->tk_msg.rpc_cred->cr_auth;
 	unsigned int replen;
 	u32 count = args->count;
 
@@ -541,7 +541,7 @@
 static int
 nfs_xdr_readlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs_readlinkargs *args)
 {
-	struct rpc_auth *auth = req->rq_task->tk_auth;
+	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
 	unsigned int replen;
 
 	p = xdr_encode_fhandle(p, args->fh);