style: gofumpt all the things (#9829)

Literally `gofumpt -w .` from the top level dir. Guaranteed to be minor
style changes only and nothing else.

@imsodin per request?

lib/model/debug.go

@@ -10,9 +10,7 @@ import (
 	"github.com/syncthing/syncthing/lib/logger"
 )
 
-var (
-	l = logger.DefaultLogger.NewFacility("model", "The root hub")
-)
+var l = logger.DefaultLogger.NewFacility("model", "The root hub")
 
 func shouldDebug() bool {
 	return l.ShouldDebug("model")