util/ringbuffer: rename to ringlog

I need a ringbuffer in the more traditional sense, one that has a notion
of item removal as well as tail loss on overrun. This implementation is
really a clearable log window, and is used as such where it is used.

Updates #cleanup
Updates tailscale/corp#31762

Signed-off-by: James Tucker <james@tailscale.com>

wgengine/magicsock/endpoint.go

@@ -33,7 +33,7 @@ import (
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/mak"
-	"tailscale.com/util/ringbuffer"
+	"tailscale.com/util/ringlog"
 	"tailscale.com/util/slicesx"
 )
 
@@ -60,7 +60,7 @@ type endpoint struct {
 	lastRecvWG            mono.Time // last time there were incoming packets from this peer destined for wireguard-go (e.g. not disco)
 	lastRecvUDPAny        mono.Time // last time there were incoming UDP packets from this peer of any kind
 	numStopAndResetAtomic int64
-	debugUpdates          *ringbuffer.RingBuffer[EndpointChange]
+	debugUpdates          *ringlog.RingLog[EndpointChange]
 
 	// These fields are initialized once and never modified.
 	c            *Conn

wgengine/magicsock/magicsock.go

@@ -62,7 +62,7 @@ import (
 	"tailscale.com/util/clientmetric"
 	"tailscale.com/util/eventbus"
 	"tailscale.com/util/mak"
-	"tailscale.com/util/ringbuffer"
+	"tailscale.com/util/ringlog"
 	"tailscale.com/util/set"
 	"tailscale.com/util/testenv"
 	"tailscale.com/util/usermetric"
@@ -3112,7 +3112,7 @@ func (c *Conn) updateNodes(update NodeViewsUpdate) (peersChanged bool) {
 			// ~1MB on mobile but we never used the data so the memory was just
 			// wasted.
 		default:
-			ep.debugUpdates = ringbuffer.New[EndpointChange](entriesPerBuffer)
+			ep.debugUpdates = ringlog.New[EndpointChange](entriesPerBuffer)
 		}
 		if n.Addresses().Len() > 0 {
 			ep.nodeAddr = n.Addresses().At(0).Addr()