SUNRPC: Move the bound cred to struct rpc_rqst

This will allow us to save the original generic cred in rpc_message, so
that if we migrate from one server to another, we can generate a new bound
cred without having to punt back to the NFS layer.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/xprt.h

@@ -64,6 +64,7 @@ struct rpc_rqst {
 	 * This is the private part
 	 */
 	struct rpc_task *	rq_task;	/* RPC task data */
+	struct rpc_cred *	rq_cred;	/* Bound cred */
 	__be32			rq_xid;		/* request XID */
 	int			rq_cong;	/* has incremented xprt->cong */
 	u32			rq_seqno;	/* gss seq no. used on req. */