refactor(relay): remove redundant uint16 conversion in coil write calls

The WriteMultipleCoils method already accepts int as the first argument,
making the explicit uint16(0) conversion unnecessary.

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

pkg/relay/relay.go

@@ -40,12 +40,12 @@ func (r *device) Close() error {
 }
 
 func (r *device) OnAll() error {
-	_, err := r.c.WriteMultipleCoils(uint16(0), 16, []byte{0xFF, 0xFF})
+	_, err := r.c.WriteMultipleCoils(0, 16, []byte{0xFF, 0xFF})
 	return err
 }
 
 func (r *device) OffAll() error {
-	_, err := r.c.WriteMultipleCoils(uint16(0), 16, []byte{0x00, 0x00})
+	_, err := r.c.WriteMultipleCoils(0, 16, []byte{0x00, 0x00})
 	return err
 }