safesocket: make ConnectDefault use paths pkg, fixing tailscaled-on-macOS

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/tailscale/depaware.txt

@@ -33,7 +33,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/net/tlsdial                                    from tailscale.com/derp/derphttp
         tailscale.com/net/tsaddr                                     from tailscale.com/net/interfaces
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/derp/derphttp+
-        tailscale.com/paths                                          from tailscale.com/cmd/tailscale/cli
+        tailscale.com/paths                                          from tailscale.com/cmd/tailscale/cli+
         tailscale.com/safesocket                                     from tailscale.com/cmd/tailscale/cli
      💣 tailscale.com/syncs                                          from tailscale.com/net/interfaces+
         tailscale.com/tailcfg                                        from tailscale.com/cmd/tailscale/cli+

safesocket/safesocket.go

@@ -10,6 +10,8 @@ import (
 	"errors"
 	"net"
 	"runtime"
+
+	"tailscale.com/paths"
 )
 
 type closeable interface {
@@ -31,7 +33,7 @@ func ConnCloseWrite(c net.Conn) error {
 
 // ConnectDefault connects to the local Tailscale daemon.
 func ConnectDefault() (net.Conn, error) {
-	return Connect("/var/run/tailscale/tailscaled.sock", 41112)
+	return Connect(paths.DefaultTailscaledSocket(), 41112)
 }
 
 // Connect connects to either path (on Unix) or the provided localhost port (on Windows).