encoding/json: adjust comment to keep the same style as comment above

src/encoding/json/decode.go

@@ -844,7 +844,7 @@ var numberType = reflect.TypeFor[Number]()
 func (d *decodeState) literalStore(item []byte, v reflect.Value, fromQuoted bool) error {
 	// Check for unmarshaler.
 	if len(item) == 0 {
-		//Empty string given
+		// Empty string given.
 		d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
 		return nil
 	}