SUNRPC: Move xprt_update_rtt callsite

Since commit 33849792cbcd ("xprtrdma: Detect unreachable NFS/RDMA
servers more reliably"), the xprtrdma transport now has a ->timer
callout. But xprtrdma does not need to compute RTT data, only UDP
needs that. Move the xprt_update_rtt call into the UDP transport
implementation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index a6b8c1f..61df77f 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1060,6 +1060,7 @@ static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
 	if (!rovr)
 		goto out_unlock;
 	xprt_pin_rqst(rovr);
+	xprt_update_rtt(rovr->rq_task);
 	spin_unlock(&xprt->recv_lock);
 	task = rovr->rq_task;