all: fix more typos caused by unnecessary repetition

Updates #cleanup

Change-Id: I5c0b8f0152581231252ab97dd1820d8b3fcbe450
Signed-off-by: Alex Chan <alexc@tailscale.com>

wgengine/magicsock/magicsock.go

@@ -2401,7 +2401,7 @@ func (c *Conn) handleDiscoMessage(msg []byte, src epAddr, shouldBeRelayHandshake
 		if isCached {
 			metricCachedPeerContactDERP.Add(1)
 		}
-		// If we did not already have an an endpoint for this peer, even a stale
+		// If we did not already have an endpoint for this peer, even a stale
 		// one, record how long it has been since the endpoint was initialized.
 		if !lastBest.ap.IsValid() {
 			c.logf("magicsock: new contact: peer=%s usec=%d cached=%v via=derp",

wgengine/magicsock/magicsock_test.go

@@ -579,7 +579,7 @@ func TestPickDERPFallback(t *testing.T) {
 		}
 	}
 
-	// Test that that the pointer value of c is blended in and
+	// Test that the pointer value of c is blended in and
 	// distribution over nodes works.
 	got := map[int]int{}
 	for range 50 {
@@ -1520,7 +1520,7 @@ func TestDiscoStringLogRace(t *testing.T) {
 	wg.Wait()
 }
 
-// Test32bitAlignment verifies that that the 64-bit atomic mono.Time fields are
+// Test32bitAlignment verifies that the 64-bit atomic mono.Time fields are
 // 64-bit aligned, so that StoreAtomic and LoadAtomic won't panic on 32-bit
 // platforms.
 //