SUNRPC: Eliminate task->tk_xprt accesses that bypass rcu_dereference()

tk_xprt is just a shortcut for tk_client->cl_xprt, however cl_xprt is
defined as an __rcu variable. Replace dereferences of tk_xprt with
non-rcu dereferences where it is safe to do so.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 9a66c95..cc1445d 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -235,13 +235,13 @@
 };
 
 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
-	(rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_rsize)
+	(rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
 
 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
-	(rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_wsize)
+	(rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
 
 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
-	rpcx_to_rdmad(rq->rq_task->tk_xprt).padding
+	rpcx_to_rdmad(rq->rq_xprt).padding
 
 /*
  * Statistics for RPCRDMA