wgengine: remove all peer status from open timeout diagnostics

Avoid contention from fetching status for all peers, and instead fetch
status for a single peer.

Updates tailscale/coral#72
Signed-off-by: James Tucker <james@tailscale.com>

wgengine/watchdog_test.go

@@ -5,14 +5,9 @@
 package wgengine
 
 import (
-	"fmt"
-	"regexp"
 	"runtime"
-	"strings"
 	"testing"
 	"time"
-
-	"tailscale.com/tstest"
 )
 
 func TestWatchdog(t *testing.T) {
@@ -42,49 +37,4 @@ func TestWatchdog(t *testing.T) {
 		e.RequestStatus()
 		e.Close()
 	})
-
-	t.Run("watchdog fires on blocked getStatus", func(t *testing.T) {
-		t.Parallel()
-		e, err := NewFakeUserspaceEngine(t.Logf, 0)
-		if err != nil {
-			t.Fatal(err)
-		}
-		t.Cleanup(e.Close)
-		usEngine := e.(*userspaceEngine)
-		e = NewWatchdog(e)
-		wdEngine := e.(*watchdogEngine)
-		wdEngine.maxWait = maxWaitMultiple * 100 * time.Millisecond
-
-		logBuf := new(tstest.MemLogger)
-		fatalCalled := make(chan struct{})
-		wdEngine.logf = logBuf.Logf
-		wdEngine.fatalf = func(format string, args ...any) {
-			t.Logf("FATAL: %s", fmt.Sprintf(format, args...))
-			fatalCalled <- struct{}{}
-		}
-
-		usEngine.wgLock.Lock() // blocks getStatus so the watchdog will fire
-
-		go e.RequestStatus()
-
-		select {
-		case <-fatalCalled:
-			logs := logBuf.String()
-			if !strings.Contains(logs, "goroutine profile: total ") {
-				t.Errorf("fatal called without watchdog stacks, got: %s", logs)
-			}
-			re := regexp.MustCompile(`(?m)^\s*in-flight\[\d+\]: name=RequestStatus duration=.* start=.*$`)
-			if !re.MatchString(logs) {
-				t.Errorf("fatal called without in-flight list, got: %s", logs)
-			}
-
-			// expected
-		case <-time.After(3 * time.Second):
-			t.Fatalf("watchdog failed to fire")
-		}
-
-		usEngine.wgLock.Unlock()
-		wdEngine.fatalf = t.Fatalf
-		wdEngine.Close()
-	})
 }