portlist: stop logging stray UDP ports

These "weird" port lines show up in logs frequently.
They're the result of uninteresting races,
and they're not actionable. Remove the noise.

Remove the isLoopbackAddr case to placate staticcheck.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

portlist/portlist_macos.go

@@ -12,7 +12,6 @@
 	"bytes"
 	"fmt"
 	"log"
-	"os"
 	"os/exec"
 	"strings"
 	"sync/atomic"
@@ -99,10 +98,8 @@ type ProtoPort struct {
 				switch {
 				case p != nil:
 					p.Process = cmd
-				case isLoopbackAddr(val):
-					// ignore
 				default:
-					fmt.Fprintf(os.Stderr, "weird: missing %v\n", pp)
+					// ignore: processes and ports come and go
 				}
 			}
 		}