all: fix typos where we repeat repeat ourselves

Found with the regex `\b([A-Za-z]+) \1\b`.

Updates #cleanup

Change-Id: I4cc51784d9b6437d3d0c66b531828707f87f7fd5
Signed-off-by: Alex Chan <alexc@tailscale.com>

cmd/tailscale/cli/jsonoutput/tailnet-lock-status.go

@@ -148,7 +148,7 @@ type tailnetLockEnabledStatusV1 struct {
 	TrustedKeys []tkaKeyV1
 
 	// VisiblePeers describes peers which are visible in the netmap that
-	// have valid Tailnet Lock signatures signatures.
+	// have valid Tailnet Lock signatures.
 	VisiblePeers []tkaTrustedPeerV1
 
 	// FilteredPeers describes peers which were removed from the netmap

cmd/tailscaled/install_darwin.go

@@ -123,7 +123,7 @@ func installSystemDaemonDarwin(args []string) (err error) {
 		return err
 	}
 
-	// Do not overwrite targetBin with the binary file if it it's already
+	// Do not overwrite targetBin with the binary file if it's already
 	// pointing to it. This is primarily to handle Homebrew that writes
 	// /usr/local/bin/tailscaled is a symlink to the actual binary.
 	if !same {

cmd/testwrapper/testwrapper.go

@@ -789,7 +789,7 @@ func main() {
 		for tr := range ch {
 			// Go assigns the package name "command-line-arguments" when you
 			// `go test FILE` rather than `go test PKG`. It's more
-			// convenient for us to to specify files in tests, so fix tr.pkg
+			// convenient for us to specify files in tests, so fix tr.pkg
 			// so that subsequent testwrapper attempts run correctly.
 			if tr.pkg == "command-line-arguments" {
 				tr.pkg = packages[0]